NavigationThrottleRunner2: void CreateThrottlesForNavigation

Change the CreateThrottlesForNavigation's signature to deprecate
legacy registration approach, returning a vector.

Bug: 412524375
Change-Id: Ia7bc8b6ed7e8407ef3b0b3d2e559a7a1c12b5638
Cq-Include-Trybots: luci.chromium.try:android-cast-arm64-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6493688
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Commit-Queue: Takashi Toyoshima <toyoshim@chromium.org>
Reviewed-by: Andrey Kosyakov <caseq@chromium.org>
Reviewed-by: Devlin Cronin <rdevlin.cronin@chromium.org>
Reviewed-by: Simeon Anfinrud <sanfin@chromium.org>
Reviewed-by: David Dorwin <ddorwin@chromium.org>
Reviewed-by: Nidhi Jaju <nidhijaju@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1456795}

android_webview/browser/aw_content_browser_client.cc

@@ -662,8 +662,7 @@ void AwContentBrowserClient::OverrideWebPreferences(
       (delegate) ? delegate->isModalContextMenu() : false;
 }
 
-std::vector<std::unique_ptr<content::NavigationThrottle>>
-AwContentBrowserClient::CreateThrottlesForNavigation(
+void AwContentBrowserClient::CreateThrottlesForNavigation(
     content::NavigationThrottleRegistry& registry) {
   // We allow intercepting only navigations within main frames. This
   // is used to post onPageStarted. We handle shouldOverrideUrlLoading
@@ -711,8 +710,6 @@ AwContentBrowserClient::CreateThrottlesForNavigation(
           &navigation_handle, urlClassifier));
     }
   }
-
-  return {};
 }
 
 std::unique_ptr<content::PrefetchServiceDelegate>

android_webview/browser/aw_content_browser_client.h

@@ -149,8 +149,7 @@ class AwContentBrowserClient : public content::ContentBrowserClient {
       content::WebContents* web_contents,
       content::SiteInstance& main_frame_site,
       blink::web_pref::WebPreferences* web_prefs) override;
-  std::vector<std::unique_ptr<content::NavigationThrottle>>
-  CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       content::NavigationThrottleRegistry& registry) override;
   std::unique_ptr<content::PrefetchServiceDelegate>
   CreatePrefetchServiceDelegate(

chrome/browser/chrome_content_browser_client.cc

@@ -5395,8 +5395,7 @@ void ChromeContentBrowserClient::RemovePresentationObserver(
   }
 }
 
-std::vector<std::unique_ptr<content::NavigationThrottle>>
-ChromeContentBrowserClient::CreateThrottlesForNavigation(
+void ChromeContentBrowserClient::CreateThrottlesForNavigation(
     content::NavigationThrottleRegistry& registry) {
   // MetricsNavigationThrottle requires that it runs before NavigationThrottles
   // that may delay or cancel navigations, so only NavigationThrottles that
@@ -5767,8 +5766,6 @@ ChromeContentBrowserClient::CreateThrottlesForNavigation(
   registry.MaybeAddThrottle(
       web_app::IsolatedWebAppThrottle::MaybeCreateThrottleFor(&handle));
 #endif  // !BUILDFLAG(IS_ANDROID)
-
-  return {};
 }
 
 std::vector<std::unique_ptr<content::CommitDeferringCondition>>

chrome/browser/chrome_content_browser_client.h

@@ -635,8 +635,7 @@ class ChromeContentBrowserClient : public content::ContentBrowserClient {
                                content::WebContents* web_contents) override;
   void RemovePresentationObserver(content::PresentationObserver* observer,
                                   content::WebContents* web_contents) override;
-  std::vector<std::unique_ptr<content::NavigationThrottle>>
-  CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       content::NavigationThrottleRegistry& registry) override;
   std::vector<std::unique_ptr<content::CommitDeferringCondition>>
   CreateCommitDeferringConditionsForNavigation(

chrome/browser/extensions/extension_navigation_throttle_unittest.cc

@@ -46,11 +46,10 @@ class MockBrowserClient : public content::ContentBrowserClient {
 
   // Only construct an ExtensionNavigationThrottle so that we can test it in
   // isolation.
-  std::vector<std::unique_ptr<NavigationThrottle>> CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       content::NavigationThrottleRegistry& registry) override {
     registry.AddThrottle(std::make_unique<ExtensionNavigationThrottle>(
         &registry.GetNavigationHandle()));
-    return {};
   }
 };
 

chromecast/browser/cast_content_browser_client.cc

@@ -809,8 +809,7 @@ CastContentBrowserClient::CreateCrashHandlerHost(
 }
 #endif  // BUILDFLAG(IS_ANDROID)
 
-std::vector<std::unique_ptr<content::NavigationThrottle>>
-CastContentBrowserClient::CreateThrottlesForNavigation(
+void CastContentBrowserClient::CreateThrottlesForNavigation(
     content::NavigationThrottleRegistry& registry) {
   if (chromecast::IsFeatureEnabled(kEnableGeneralAudienceBrowsing)) {
     registry.AddThrottle(
@@ -818,8 +817,6 @@ CastContentBrowserClient::CreateThrottlesForNavigation(
             &registry.GetNavigationHandle(),
             general_audience_browsing_service_.get()));
   }
-
-  return {};
 }
 
 void CastContentBrowserClient::RegisterNonNetworkSubresourceURLLoaderFactories(

chromecast/browser/cast_content_browser_client.h

@@ -241,8 +241,7 @@ class CastContentBrowserClient
   std::unique_ptr<content::NavigationUIData> GetNavigationUIData(
       content::NavigationHandle* navigation_handle) override;
   bool ShouldEnableStrictSiteIsolation() override;
-  std::vector<std::unique_ptr<content::NavigationThrottle>>
-  CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       content::NavigationThrottleRegistry& registry) override;
   void RegisterNonNetworkSubresourceURLLoaderFactories(
       int render_process_id,

components/error_page/content/browser/net_error_auto_reloader_browsertest.cc

@@ -11,6 +11,7 @@
 #include "base/memory/raw_ptr.h"
 #include "base/test/bind.h"
 #include "content/public/browser/navigation_controller.h"
+#include "content/public/browser/navigation_throttle_registry.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_observer.h"
 #include "content/public/common/content_features.h"
@@ -43,8 +44,9 @@ class NetErrorUrlInterceptor {
         interceptor_(base::BindLambdaForTesting(
             [this,
              error](content::URLLoaderInterceptor::RequestParams* params) {
-              if (params->url_request.url != url_)
+              if (params->url_request.url != url_) {
                 return false;
+              }
               network::URLLoaderCompletionStatus status;
               status.error_code = error;
               params->client->OnComplete(status);
@@ -133,15 +135,17 @@ class DeferNextNavigationThrottleInserter
   // content::WebContentsObserver:
   void DidFinishNavigation(content::NavigationHandle* handle) override {
     DCHECK(throttle_);
-    if (handle == throttle_->navigation_handle())
+    if (handle == throttle_->navigation_handle()) {
       finish_wait_loop_.Quit();
     }
+  }
 
  private:
   std::unique_ptr<content::NavigationThrottle> MaybeCreateThrottle(
       content::NavigationHandle* handle) {
-    if (throttle_)
+    if (throttle_) {
       return nullptr;
+    }
 
     auto throttle = std::make_unique<DeferringThrottle>(
         handle, defer_wait_loop_.QuitClosure());
@@ -170,15 +174,10 @@ class NetErrorAutoReloaderBrowserTest : public content::ContentBrowserTest {
 
     content::ShellContentBrowserClient::Get()
         ->set_create_throttles_for_navigation_callback(base::BindRepeating(
-            [](content::NavigationHandle* handle)
-                -> std::vector<std::unique_ptr<content::NavigationThrottle>> {
-              std::vector<std::unique_ptr<content::NavigationThrottle>>
-                  throttles;
-              auto throttle =
-                  NetErrorAutoReloader::MaybeCreateThrottleFor(handle);
-              if (throttle)
-                throttles.push_back(std::move(throttle));
-              return throttles;
+            [](content::NavigationThrottleRegistry& registry) -> void {
+              registry.MaybeAddThrottle(
+                  NetErrorAutoReloader::MaybeCreateThrottleFor(
+                      &registry.GetNavigationHandle()));
             }));
   }
 
@@ -193,8 +192,9 @@ class NetErrorAutoReloaderBrowserTest : public content::ContentBrowserTest {
   std::optional<base::TimeDelta> GetCurrentAutoReloadDelay() {
     const std::optional<base::OneShotTimer>& timer =
         GetAutoReloader()->next_reload_timer_for_testing();
-    if (!timer)
+    if (!timer) {
       return std::nullopt;
+    }
     return timer->GetCurrentDelay();
   }
 
@@ -239,9 +239,10 @@ class NetErrorAutoReloaderBrowserTest : public content::ContentBrowserTest {
         error_page::NetErrorAutoReloader::FromWebContents(wc);
     std::optional<base::OneShotTimer>& timer =
         reloader->next_reload_timer_for_testing();
-    if (timer && timer->IsRunning())
+    if (timer && timer->IsRunning()) {
       timer->FireNow();
     }
+  }
 
   static void SimulateNetworkGoingOnline(content::WebContents* wc) {
     error_page::NetErrorAutoReloader* reloader =

components/page_load_metrics/browser/page_load_metrics_test_content_browser_client.cc

@@ -19,15 +19,13 @@ PageLoadMetricsTestContentBrowserClient::
 PageLoadMetricsTestContentBrowserClient::
     ~PageLoadMetricsTestContentBrowserClient() = default;
 
-std::vector<std::unique_ptr<content::NavigationThrottle>>
-PageLoadMetricsTestContentBrowserClient::CreateThrottlesForNavigation(
+void PageLoadMetricsTestContentBrowserClient::CreateThrottlesForNavigation(
     content::NavigationThrottleRegistry& registry) {
   content::NavigationHandle& navigation_handle = registry.GetNavigationHandle();
   if (navigation_handle.IsInMainFrame()) {
     registry.AddThrottle(page_load_metrics::MetricsNavigationThrottle::Create(
         &navigation_handle));
   }
-  return {};
 }
 
 }  // namespace page_load_metrics

components/page_load_metrics/browser/page_load_metrics_test_content_browser_client.h

@@ -24,8 +24,7 @@ class PageLoadMetricsTestContentBrowserClient
   ~PageLoadMetricsTestContentBrowserClient() override;
 
   // content::ContentBrowserClient:
-  std::vector<std::unique_ptr<content::NavigationThrottle>>
-  CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       content::NavigationThrottleRegistry& registry) override;
 };
 

content/browser/back_forward_cache_internal_browsertest.cc

@@ -3516,10 +3516,9 @@ IN_PROC_BROWSER_TEST_F(BackForwardCacheBrowserTest, NoThrottlesOnCacheRestore) {
   // NavigationThrottles.
   content::ShellContentBrowserClient::Get()
       ->set_create_throttles_for_navigation_callback(base::BindLambdaForTesting(
-          [&did_register_throttles](content::NavigationHandle* handle)
-              -> std::vector<std::unique_ptr<content::NavigationThrottle>> {
+          [&did_register_throttles](
+              content::NavigationThrottleRegistry& registry) -> void {
             did_register_throttles = true;
-            return std::vector<std::unique_ptr<content::NavigationThrottle>>();
           }));
 
   // 2) Navigate to B.

content/browser/preloading/prerender/prerender_browsertest.cc

@@ -4101,8 +4101,9 @@ class RedirectChainObserver : public WebContentsObserver {
 
  private:
   void DidFinishNavigation(NavigationHandle* handle) override {
-    if (handle->GetURL() != url_)
+    if (handle->GetURL() != url_) {
       return;
+    }
     redirect_chain_ = handle->GetRedirectChain();
   }
 
@@ -5409,8 +5410,9 @@ class IsActivationObserver : public WebContentsObserver {
 
  private:
   void DidStartNavigation(NavigationHandle* handle) override {
-    if (handle->GetURL() != url_)
+    if (handle->GetURL() != url_) {
       return;
+    }
     did_navigate_ = true;
     was_activation_ = handle->IsPrerenderedPageActivation();
   }
@@ -5470,20 +5472,16 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest, ActivationDoesntRunThrottles) {
   // WillStartRequest into all new navigations.
   ShellContentBrowserClient::Get()
       ->set_create_throttles_for_navigation_callback(base::BindLambdaForTesting(
-          [&throttle](NavigationHandle* handle)
-              -> std::vector<std::unique_ptr<NavigationThrottle>> {
-            std::vector<std::unique_ptr<NavigationThrottle>> throttles;
-
-            auto throttle_ptr =
-                std::make_unique<TestNavigationThrottle>(handle);
+          [&throttle](NavigationThrottleRegistry& registry) -> void {
+            auto throttle_ptr = std::make_unique<TestNavigationThrottle>(
+                &registry.GetNavigationHandle());
             CHECK(!throttle);
             throttle = throttle_ptr.get();
             throttle_ptr->SetResponse(
                 TestNavigationThrottle::WILL_START_REQUEST,
                 TestNavigationThrottle::SYNCHRONOUS, NavigationThrottle::DEFER);
 
-            throttles.push_back(std::move(throttle_ptr));
-            return throttles;
+            registry.AddThrottle(std::move(throttle_ptr));
           }));
 
   // Start a prerender and ensure that a NavigationThrottle can defer the
@@ -5768,13 +5766,11 @@ IN_PROC_BROWSER_TEST_F(PrerenderBrowserTest,
   // before PrerenderSubframeNavigationThrottle.
   ShellContentBrowserClient::Get()
       ->set_create_throttles_for_navigation_callback(base::BindLambdaForTesting(
-          [](NavigationHandle* handle)
-              -> std::vector<std::unique_ptr<NavigationThrottle>> {
-            std::vector<std::unique_ptr<NavigationThrottle>> throttles;
-            throttles.push_back(
+          [](NavigationThrottleRegistry& registry) -> void {
+            registry.AddThrottle(
                 std::make_unique<
-                    TestPrerenderCancellerSubframeNavigationThrottle>(handle));
-            return throttles;
+                    TestPrerenderCancellerSubframeNavigationThrottle>(
+                    &registry.GetNavigationHandle()));
           }));
 
   // Use ExecuteScriptAsync instead of EvalJs as inserted cross-origin iframe
@@ -6654,8 +6650,9 @@ IN_PROC_BROWSER_TEST_P(SSLPrerenderBrowserTest,
   // Skip the test when the block type is kCertError. With the type, this test
   // times out due to https://crbug.com/1311887.
   // TODO(crbug.com/40220378): Enable the test with kCertError.
-  if (GetParam() == SSLPrerenderTestErrorBlockType::kCertError)
+  if (GetParam() == SSLPrerenderTestErrorBlockType::kCertError) {
     return;
+  }
 
   // Load an initial page and register a service worker that intercepts
   // resources requests.
@@ -8061,8 +8058,9 @@ IN_PROC_BROWSER_TEST_F(PrerenderSequentialPrerenderingBrowserTest,
 
   // Confirm that all the other prerender hosts are successfully cancelled.
   for (auto& url : prerender_urls) {
-    if (url == prerender_urls[0])
+    if (url == prerender_urls[0]) {
       continue;
+    }
     EXPECT_TRUE(GetHostForUrl(url).is_null());
   }
 
@@ -11999,12 +11997,13 @@ class FrameDisplayStateChangedObserver : public WebContentsObserver {
   void FrameDisplayStateChanged(RenderFrameHost* host,
                                 bool is_display_none) override {
     if (host == target_host_) {
-      if (callback_)
+      if (callback_) {
         std::move(callback_).Run();
-      else
+      } else {
         changed_count_++;
       }
     }
+  }
 
   int changed_count_ = 0;
   const raw_ptr<RenderFrameHost> target_host_;
@@ -12509,8 +12508,9 @@ class PrerenderRequestHeadersBrowserTest : public PrerenderBrowserTest {
     // Note: Checking the origin of `request.GetURL()` doesn't work here because
     // the host part of the URL is translated (e.g., "a.test" to "127.0.0.1")
     // based on the host resolver rule before this point.
-    if (request.relative_url.find("cors") == std::string::npos)
+    if (request.relative_url.find("cors") == std::string::npos) {
       return nullptr;
+    }
 
     // Serves a fake response with the ACAO header.
     auto response = std::make_unique<net::test_server::BasicHttpResponse>();
@@ -13257,8 +13257,9 @@ IN_PROC_BROWSER_TEST_F(PrerenderFencedFrameBrowserTest,
   // child frames.
   size_t child_frame_count = 0;
   prerendered_rfh->ForEachRenderFrameHostImpl([&](RenderFrameHostImpl* rfh) {
-    if (rfh != prerendered_rfh)
+    if (rfh != prerendered_rfh) {
       child_frame_count++;
+    }
   });
   EXPECT_EQ(0lu, child_frame_count);
 
@@ -13444,8 +13445,9 @@ class PrerenderClientHintsBrowserTest : public PrerenderBrowserTest {
 
   static std::unique_ptr<net::test_server::HttpResponse> HandleRequest(
       const net::test_server::HttpRequest& request) {
-    if (request.relative_url.find("acceptch") == std::string::npos)
+    if (request.relative_url.find("acceptch") == std::string::npos) {
       return nullptr;
+    }
 
     // Serve a response indicating clients to provide full version of UA.
     auto response = std::make_unique<net::test_server::BasicHttpResponse>();

content/browser/renderer_host/navigation_request_browsertest.cc

@@ -272,32 +272,36 @@ class TestNavigationThrottleInstaller : public WebContentsObserver {
   TestNavigationThrottle* navigation_throttle() { return navigation_throttle_; }
 
   void WaitForThrottleWillStart() {
-    if (will_start_called_)
+    if (will_start_called_) {
       return;
+    }
     will_start_loop_runner_ = new MessageLoopRunner();
     will_start_loop_runner_->Run();
     will_start_loop_runner_ = nullptr;
   }
 
   void WaitForThrottleWillRedirect() {
-    if (will_redirect_called_)
+    if (will_redirect_called_) {
       return;
+    }
     will_redirect_loop_runner_ = new MessageLoopRunner();
     will_redirect_loop_runner_->Run();
     will_redirect_loop_runner_ = nullptr;
   }
 
   void WaitForThrottleWillFail() {
-    if (will_fail_called_)
+    if (will_fail_called_) {
       return;
+    }
     will_fail_loop_runner_ = new MessageLoopRunner();
     will_fail_loop_runner_->Run();
     will_fail_loop_runner_ = nullptr;
   }
 
   void WaitForThrottleWillProcess() {
-    if (will_process_called_)
+    if (will_process_called_) {
       return;
+    }
     will_process_loop_runner_ = new MessageLoopRunner();
     will_process_loop_runner_->Run();
     will_process_loop_runner_ = nullptr;
@@ -314,11 +318,12 @@ class TestNavigationThrottleInstaller : public WebContentsObserver {
 
   void Continue(NavigationThrottle::ThrottleCheckResult result) {
     ASSERT_NE(NavigationThrottle::DEFER, result.action());
-    if (result.action() == NavigationThrottle::PROCEED)
+    if (result.action() == NavigationThrottle::PROCEED) {
       navigation_throttle()->ResumeNavigation();
-    else
+    } else {
       navigation_throttle()->CancelNavigation(result);
     }
+  }
 
   int will_start_called() { return will_start_called_; }
   int will_redirect_called() { return will_redirect_called_; }
@@ -333,27 +338,31 @@ class TestNavigationThrottleInstaller : public WebContentsObserver {
  protected:
   virtual void DidCallWillStartRequest() {
     will_start_called_++;
-    if (will_start_loop_runner_)
+    if (will_start_loop_runner_) {
       will_start_loop_runner_->Quit();
     }
+  }
 
   virtual void DidCallWillRedirectRequest() {
     will_redirect_called_++;
-    if (will_redirect_loop_runner_)
+    if (will_redirect_loop_runner_) {
       will_redirect_loop_runner_->Quit();
     }
+  }
 
   virtual void DidCallWillFailRequest() {
     will_fail_called_++;
-    if (will_fail_loop_runner_)
+    if (will_fail_loop_runner_) {
       will_fail_loop_runner_->Quit();
     }
+  }
 
   virtual void DidCallWillProcessResponse() {
     will_process_called_++;
-    if (will_process_loop_runner_)
+    if (will_process_loop_runner_) {
       will_process_loop_runner_->Quit();
     }
+  }
 
   virtual void DidCallWillCommitWithoutUrlLoader() {
     will_commit_without_url_loader_called_++;
@@ -365,8 +374,9 @@ class TestNavigationThrottleInstaller : public WebContentsObserver {
  private:
   void DidStartNavigation(NavigationHandle* handle) override {
     if (!expected_start_url_.is_empty() &&
-        handle->GetURL() != expected_start_url_)
+        handle->GetURL() != expected_start_url_) {
       return;
+    }
 
     std::unique_ptr<NavigationThrottle> throttle(new TestNavigationThrottle(
         handle, will_start_result_, will_redirect_result_, will_fail_result_,
@@ -391,12 +401,14 @@ class TestNavigationThrottleInstaller : public WebContentsObserver {
   }
 
   void DidFinishNavigation(NavigationHandle* handle) override {
-    if (!navigation_throttle_)
+    if (!navigation_throttle_) {
       return;
+    }
 
-    if (handle == navigation_throttle_->navigation_handle())
+    if (handle == navigation_throttle_->navigation_handle()) {
       navigation_throttle_ = nullptr;
     }
+  }
 
   NavigationThrottle::ThrottleCheckResult will_start_result_;
   NavigationThrottle::ThrottleCheckResult will_redirect_result_;
@@ -2663,19 +2675,17 @@ IN_PROC_BROWSER_TEST_F(NavigationRequestBrowserTest,
   // |client_throttle| when its registered.
   content::ShellContentBrowserClient::Get()
       ->set_create_throttles_for_navigation_callback(base::BindLambdaForTesting(
-          [&client_throttle](content::NavigationHandle* handle)
-              -> std::vector<std::unique_ptr<content::NavigationThrottle>> {
-            std::vector<std::unique_ptr<content::NavigationThrottle>> throttles;
+          [&client_throttle](
+              content::NavigationThrottleRegistry& registry) -> void {
             std::unique_ptr<TestNavigationThrottle> throttle(
                 new TestNavigationThrottle(
-                    handle, NavigationThrottle::DEFER,
+                    &registry.GetNavigationHandle(), NavigationThrottle::DEFER,
                     NavigationThrottle::PROCEED, NavigationThrottle::PROCEED,
                     NavigationThrottle::PROCEED, NavigationThrottle::PROCEED,
                     base::DoNothing(), base::DoNothing(), base::DoNothing(),
                     base::DoNothing(), base::DoNothing()));
             client_throttle = throttle.get();
-            throttles.push_back(std::move(throttle));
-            return throttles;
+            registry.AddThrottle(std::move(throttle));
           }));
 
   // Add another similar throttle using the installer which will use
@@ -2938,9 +2948,10 @@ IN_PROC_BROWSER_TEST_F(NavigationRequestBrowserTest_IsolateAllSites,
     auto add_suffix = [&names](std::vector<std::string> suffixes) {
       size_t original_size = names.size();
       for (size_t i = 0; i < original_size; i++) {
-        for (const std::string& suffix : suffixes)
+        for (const std::string& suffix : suffixes) {
           names.push_back(names[i] + suffix);
         }
+      }
     };
     add_suffix({kProcessSuffixes.at(process_type)});
     add_suffix({kFrameSuffixes.at(frame_type)});
@@ -4689,14 +4700,12 @@ IN_PROC_BROWSER_TEST_F(NavigationRequestResponseBodyBrowserTest, Received) {
   // to this throttle in `client_throttle` on registration.
   content::ShellContentBrowserClient::Get()
       ->set_create_throttles_for_navigation_callback(base::BindLambdaForTesting(
-          [&client_throttle](content::NavigationHandle* handle)
-              -> std::vector<std::unique_ptr<content::NavigationThrottle>> {
-            std::vector<std::unique_ptr<content::NavigationThrottle>> throttles;
-            auto throttle =
-                std::make_unique<ResponseBodyNavigationThrottle>(handle);
+          [&client_throttle](
+              content::NavigationThrottleRegistry& registry) -> void {
+            auto throttle = std::make_unique<ResponseBodyNavigationThrottle>(
+                &registry.GetNavigationHandle());
             client_throttle = throttle.get();
-            throttles.push_back(std::move(throttle));
-            return throttles;
+            registry.AddThrottle(std::move(throttle));
           }));
 
   // Start navigating.
@@ -4732,14 +4741,12 @@ IN_PROC_BROWSER_TEST_F(NavigationRequestResponseBodyBrowserTest,
   // to this throttle in `client_throttle` on registration.
   content::ShellContentBrowserClient::Get()
       ->set_create_throttles_for_navigation_callback(base::BindLambdaForTesting(
-          [&client_throttle](content::NavigationHandle* handle)
-              -> std::vector<std::unique_ptr<content::NavigationThrottle>> {
-            std::vector<std::unique_ptr<content::NavigationThrottle>> throttles;
-            auto throttle =
-                std::make_unique<ResponseBodyNavigationThrottle>(handle);
+          [&client_throttle](
+              content::NavigationThrottleRegistry& registry) -> void {
+            auto throttle = std::make_unique<ResponseBodyNavigationThrottle>(
+                &registry.GetNavigationHandle());
             client_throttle = throttle.get();
-            throttles.push_back(std::move(throttle));
-            return throttles;
+            registry.AddThrottle(std::move(throttle));
           }));
 
   // Start navigating.
@@ -4775,14 +4782,12 @@ IN_PROC_BROWSER_TEST_F(NavigationRequestResponseBodyBrowserTest,
   // to this throttle in `client_throttle` on registration.
   content::ShellContentBrowserClient::Get()
       ->set_create_throttles_for_navigation_callback(base::BindLambdaForTesting(
-          [&client_throttle](content::NavigationHandle* handle)
-              -> std::vector<std::unique_ptr<content::NavigationThrottle>> {
-            std::vector<std::unique_ptr<content::NavigationThrottle>> throttles;
-            auto throttle =
-                std::make_unique<ResponseBodyNavigationThrottle>(handle);
+          [&client_throttle](
+              content::NavigationThrottleRegistry& registry) -> void {
+            auto throttle = std::make_unique<ResponseBodyNavigationThrottle>(
+                &registry.GetNavigationHandle());
             client_throttle = throttle.get();
-            throttles.push_back(std::move(throttle));
-            return throttles;
+            registry.AddThrottle(std::move(throttle));
           }));
 
   // Start navigating to a page with a large body (>5 million characters).

content/browser/renderer_host/navigation_request_unittest.cc

@@ -592,13 +592,11 @@ class GetRenderFrameHostOnFailureNavigationThrottle
 };
 
 class ThrottleTestContentBrowserClient : public ContentBrowserClient {
-  std::vector<std::unique_ptr<NavigationThrottle>> CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       NavigationThrottleRegistry& registry) override {
-    std::vector<std::unique_ptr<NavigationThrottle>> throttle;
     registry.AddThrottle(
         std::make_unique<GetRenderFrameHostOnFailureNavigationThrottle>(
             &registry.GetNavigationHandle()));
-    return throttle;
   }
 };
 

content/browser/renderer_host/navigation_throttle_runner.cc

@@ -218,16 +218,7 @@ void NavigationThrottleRunner::RegisterNavigationThrottles() {
   // NavigationRequest.
   NavigationRequest* request = static_cast<NavigationRequest*>(delegate_);
 
-  std::vector<std::unique_ptr<NavigationThrottle>> throttles_under_migration =
   request->GetDelegate()->CreateThrottlesForNavigation(*this);
-  // TODO(https://crbug.com/412524375): Remove `throttles_under_migration` and
-  // following code to move them to the member variable. When the call returns
-  // above, migrated throttles are already registered in `throttles_` via the
-  // new NavigationThrottleRegistry interface. So, we cannot assign the returned
-  // vector directly to `throttles_`.
-  throttles_.insert(throttles_.end(),
-                    std::make_move_iterator(throttles_under_migration.begin()),
-                    std::make_move_iterator(throttles_under_migration.end()));
 
   // Check for renderer-inititated main frame navigations to blocked URL schemes
   // (data, filesystem). This is done early as it may block the main frame

content/browser/renderer_host/navigator_delegate.h

@@ -120,12 +120,8 @@ class NavigatorDelegate {
   // Returns the NavigationThrottles to add to this navigation. Normally these
   // are defined by the content/ embedder, except in the case of interstitials
   // where no NavigationThrottles are added to the navigation.
-  // TODO(https://crbug.com/412524375): New code should add a NavigationThrottle
-  // via the given `registry` instead of returning a NavigationThrottle from
-  // this method. Once all existing NavigationThrottles are migrated, the
-  // returned type will be changed to `void`.
-  virtual std::vector<std::unique_ptr<NavigationThrottle>>
-  CreateThrottlesForNavigation(NavigationThrottleRegistry& registry) = 0;
+  virtual void CreateThrottlesForNavigation(
+      NavigationThrottleRegistry& registry) = 0;
 
   // Returns commit deferring conditions to add to this navigation.
   virtual std::vector<std::unique_ptr<CommitDeferringCondition>>

content/browser/web_contents/web_contents_impl.cc

@@ -9534,13 +9534,12 @@ bool WebContentsImpl::IsHidden() {
   return GetPageVisibilityState() == PageVisibilityState::kHidden;
 }
 
-std::vector<std::unique_ptr<NavigationThrottle>>
-WebContentsImpl::CreateThrottlesForNavigation(
+void WebContentsImpl::CreateThrottlesForNavigation(
     NavigationThrottleRegistry& registry) {
   OPTIONAL_TRACE_EVENT1("content",
                         "WebContentsImpl::CreateThrottlesForNavigation",
                         "navigation", registry.GetNavigationHandle());
-  return GetContentClient()->browser()->CreateThrottlesForNavigation(registry);
+  GetContentClient()->browser()->CreateThrottlesForNavigation(registry);
 }
 
 std::vector<std::unique_ptr<CommitDeferringCondition>>

content/browser/web_contents/web_contents_impl.h

@@ -1067,7 +1067,7 @@ class CONTENT_EXPORT WebContentsImpl
       bool is_outermost_main_frame_navigation) override;
   const blink::UserAgentOverride& GetUserAgentOverride(
       FrameTree& frame_tree) override;
-  std::vector<std::unique_ptr<NavigationThrottle>> CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       NavigationThrottleRegistry& registry) override;
   std::vector<std::unique_ptr<CommitDeferringCondition>>
   CreateDeferringConditionsForNavigationCommit(

content/public/browser/content_browser_client.cc

@@ -997,11 +997,8 @@ void ContentBrowserClient::OpenURL(
   std::move(callback).Run(nullptr);
 }
 
-std::vector<std::unique_ptr<NavigationThrottle>>
-content::ContentBrowserClient::CreateThrottlesForNavigation(
-    NavigationThrottleRegistry& registry) {
-  return std::vector<std::unique_ptr<NavigationThrottle>>();
-}
+void ContentBrowserClient::CreateThrottlesForNavigation(
+    NavigationThrottleRegistry& registry) {}
 
 std::vector<std::unique_ptr<CommitDeferringCondition>>
 ContentBrowserClient::CreateCommitDeferringConditionsForNavigation(

content/public/browser/content_browser_client.h

@@ -1705,12 +1705,8 @@ class CONTENT_EXPORT ContentBrowserClient {
   // navigations; they are specifically not run for page activating navigations
   // such as prerender activation and back-forward cache restores or for
   // navigations that don't use a URLLoader like same-document navigations.
-  // TODO(https://crbug.com/412524375): New code should add a NavigationThrottle
-  // via the given `registry` instead of returning a NavigationThrottle from
-  // this method. Once all existing NavigationThrottles are migrated, the
-  // returned type will be changed to `void`.
-  virtual std::vector<std::unique_ptr<NavigationThrottle>>
-  CreateThrottlesForNavigation(NavigationThrottleRegistry& registry);
+  virtual void CreateThrottlesForNavigation(
+      NavigationThrottleRegistry& registry);
 
   // Allows the embedder to register one or more CommitDeferringConditions for
   // the navigation indicated by |navigation_handle|. A

content/shell/browser/shell_content_browser_client.cc

@@ -693,16 +693,11 @@ void ShellContentBrowserClient::OpenURL(
           ->web_contents());
 }
 
-std::vector<std::unique_ptr<NavigationThrottle>>
-ShellContentBrowserClient::CreateThrottlesForNavigation(
+void ShellContentBrowserClient::CreateThrottlesForNavigation(
     NavigationThrottleRegistry& registry) {
-  std::vector<std::unique_ptr<NavigationThrottle>> empty_throttles;
   if (create_throttles_for_navigation_callback_) {
-    // TODO(https://crbug.com/412524375): NavigationThrottleRegistry migration.
-    return create_throttles_for_navigation_callback_.Run(
-        &registry.GetNavigationHandle());
+    create_throttles_for_navigation_callback_.Run(registry);
   }
-  return empty_throttles;
 }
 
 std::unique_ptr<LoginDelegate> ShellContentBrowserClient::CreateLoginDelegate(

content/shell/browser/shell_content_browser_client.h

@@ -125,7 +125,7 @@ class ShellContentBrowserClient : public ContentBrowserClient {
   void OpenURL(SiteInstance* site_instance,
                const OpenURLParams& params,
                base::OnceCallback<void(WebContents*)> callback) override;
-  std::vector<std::unique_ptr<NavigationThrottle>> CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       NavigationThrottleRegistry& registry) override;
   std::unique_ptr<LoginDelegate> CreateLoginDelegate(
       const net::AuthChallengeInfo& auth_info,
@@ -218,8 +218,8 @@ class ShellContentBrowserClient : public ContentBrowserClient {
         std::move(url_loader_factory_params_callback);
   }
   void set_create_throttles_for_navigation_callback(
-      base::RepeatingCallback<std::vector<std::unique_ptr<NavigationThrottle>>(
-          NavigationHandle*)> create_throttles_for_navigation_callback) {
+      base::RepeatingCallback<void(NavigationThrottleRegistry&)>
+          create_throttles_for_navigation_callback) {
     create_throttles_for_navigation_callback_ =
         create_throttles_for_navigation_callback;
   }
@@ -271,8 +271,7 @@ class ShellContentBrowserClient : public ContentBrowserClient {
                                bool is_for_isolated_world,
                                bool is_for_service_worker)>
       url_loader_factory_params_callback_;
-  base::RepeatingCallback<std::vector<std::unique_ptr<NavigationThrottle>>(
-      NavigationHandle*)>
+  base::RepeatingCallback<void(NavigationThrottleRegistry&)>
       create_throttles_for_navigation_callback_;
   base::RepeatingCallback<void(blink::web_pref::WebPreferences*)>
       override_web_preferences_callback_;

content/web_test/browser/web_test_content_browser_client.cc

@@ -420,21 +420,14 @@ void WebTestContentBrowserClient::OverrideWebPreferences(
     WebTestControlHost::Get()->OverrideWebPreferences(prefs);
 }
 
-std::vector<std::unique_ptr<content::NavigationThrottle>>
-WebTestContentBrowserClient::CreateThrottlesForNavigation(
+void WebTestContentBrowserClient::CreateThrottlesForNavigation(
     content::NavigationThrottleRegistry& registry) {
-  content::NavigationHandle* navigation_handle =
-      &registry.GetNavigationHandle();
-  std::vector<std::unique_ptr<content::NavigationThrottle>> throttles =
   ShellContentBrowserClient::CreateThrottlesForNavigation(registry);
-
-  throttles.push_back(std::make_unique<WebTestOriginTrialThrottle>(
-      navigation_handle, navigation_handle->GetWebContents()
+  content::NavigationHandle& navigation_handle = registry.GetNavigationHandle();
+  registry.AddThrottle(std::make_unique<WebTestOriginTrialThrottle>(
+      &navigation_handle, navigation_handle.GetWebContents()
                               ->GetBrowserContext()
                               ->GetOriginTrialsControllerDelegate()));
-
-  // TODO(https://crbug.com/412524375): NavigationThrottleRegistry migration.
-  return throttles;
 }
 
 void WebTestContentBrowserClient::AppendExtraCommandLineSwitches(

content/web_test/browser/web_test_content_browser_client.h

@@ -75,8 +75,7 @@ class WebTestContentBrowserClient : public ShellContentBrowserClient {
   void OverrideWebPreferences(WebContents* web_contents,
                               SiteInstance& main_frame_site,
                               blink::web_pref::WebPreferences* prefs) override;
-  std::vector<std::unique_ptr<content::NavigationThrottle>>
-  CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       content::NavigationThrottleRegistry& registry) override;
   void AppendExtraCommandLineSwitches(base::CommandLine* command_line,
                                       int child_process_id) override;

extensions/shell/browser/shell_content_browser_client.cc

@@ -252,8 +252,7 @@ void ShellContentBrowserClient::
                           render_frame_host.GetGlobalId()));
 }
 
-std::vector<std::unique_ptr<content::NavigationThrottle>>
-ShellContentBrowserClient::CreateThrottlesForNavigation(
+void ShellContentBrowserClient::CreateThrottlesForNavigation(
     content::NavigationThrottleRegistry& registry) {
   content::NavigationHandle& navigation_handle =
       registry.GetNavigationHandle();
@@ -265,7 +264,6 @@ ShellContentBrowserClient::CreateThrottlesForNavigation(
   }
   registry.MaybeAddThrottle(
       WebViewGuest::MaybeCreateNavigationThrottle(&navigation_handle));
-  return {};
 }
 
 std::unique_ptr<content::NavigationUIData>

extensions/shell/browser/shell_content_browser_client.h

@@ -89,8 +89,7 @@ class ShellContentBrowserClient : public content::ContentBrowserClient {
   void RegisterAssociatedInterfaceBindersForRenderFrameHost(
       content::RenderFrameHost& render_frame_host,
       blink::AssociatedInterfaceRegistry& associated_registry) override;
-  std::vector<std::unique_ptr<content::NavigationThrottle>>
-  CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       content::NavigationThrottleRegistry& registry) override;
   std::unique_ptr<content::NavigationUIData> GetNavigationUIData(
       content::NavigationHandle* navigation_handle) override;

fuchsia_web/webengine/browser/web_engine_content_browser_client.cc

@@ -310,8 +310,7 @@ base::OnceClosure WebEngineContentBrowserClient::SelectClientCertificate(
   return base::OnceClosure();
 }
 
-std::vector<std::unique_ptr<content::NavigationThrottle>>
-WebEngineContentBrowserClient::CreateThrottlesForNavigation(
+void WebEngineContentBrowserClient::CreateThrottlesForNavigation(
     content::NavigationThrottleRegistry& registry) {
   auto& navigation_handle = registry.GetNavigationHandle();
   auto* frame_impl =
@@ -334,8 +333,6 @@ WebEngineContentBrowserClient::CreateThrottlesForNavigation(
         navigation_handle.GetWebContents()->GetBrowserContext(),
         *explicit_sites_filter_error_page));
   }
-
-  return {};
 }
 
 std::vector<std::unique_ptr<blink::URLLoaderThrottle>>

fuchsia_web/webengine/browser/web_engine_content_browser_client.h

@@ -62,8 +62,7 @@ class WebEngineContentBrowserClient final
       net::SSLCertRequestInfo* cert_request_info,
       net::ClientCertIdentityList client_certs,
       std::unique_ptr<content::ClientCertificateDelegate> delegate) override;
-  std::vector<std::unique_ptr<content::NavigationThrottle>>
-  CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       content::NavigationThrottleRegistry& registry) override;
   std::vector<std::unique_ptr<blink::URLLoaderThrottle>>
   CreateURLLoaderThrottles(

headless/lib/browser/headless_content_browser_client.cc

@@ -453,21 +453,15 @@ void HeadlessContentBrowserClient::SessionEnding(
 #endif
 
 #if defined(HEADLESS_USE_POLICY)
-std::vector<std::unique_ptr<content::NavigationThrottle>>
-HeadlessContentBrowserClient::CreateThrottlesForNavigation(
+void HeadlessContentBrowserClient::CreateThrottlesForNavigation(
     content::NavigationThrottleRegistry& registry) {
-  std::vector<std::unique_ptr<content::NavigationThrottle>> throttles;
-
   // Avoid creating naviagtion throttle if preferences are not available
   // (happens in tests).
   content::NavigationHandle& handle = registry.GetNavigationHandle();
   if (browser_->GetPrefs()) {
-    throttles.push_back(std::make_unique<PolicyBlocklistNavigationThrottle>(
+    registry.AddThrottle(std::make_unique<PolicyBlocklistNavigationThrottle>(
         &handle, handle.GetWebContents()->GetBrowserContext()));
   }
-
-  // TODO(https://crbug.com/412524375): NavigationThrottleRegistry migration.
-  return throttles;
 }
 #endif  // defined(HEADLESS_USE_POLICY)
 

headless/lib/browser/headless_content_browser_client.h

@@ -133,8 +133,7 @@ class HeadlessContentBrowserClient : public content::ContentBrowserClient {
 #endif
 
 #if defined(HEADLESS_USE_POLICY)
-  std::vector<std::unique_ptr<content::NavigationThrottle>>
-  CreateThrottlesForNavigation(
+  void CreateThrottlesForNavigation(
       content::NavigationThrottleRegistry& registry) override;
 #endif