[3PCD] Not sending labels in incognito mode

This CL also makes ContentBrowserClient to return false by default,
and override in ShellContentBrowserClient for testing.

Bug: 1485124
Change-Id: I676ed302464e9af9d6e37fe77c08983b9969a4d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4876981
Reviewed-by: Anthony Garant <anthonygarant@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Commit-Queue: Nan Lin <linnan@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1199168}

content/browser/cookie_deprecation_label/cookie_deprecation_label_browsertest.cc

@@ -520,6 +520,21 @@ IN_PROC_BROWSER_TEST_F(CookieDeprecationLabelEnabledBrowserTest,
             "label_test");
 }
 
+IN_PROC_BROWSER_TEST_F(CookieDeprecationLabelEnabledBrowserTest,
+                       Incognito_LabelError) {
+  auto https_server = CreateTestServer(EmbeddedTestServer::TYPE_HTTPS);
+  ASSERT_TRUE(https_server->Start());
+
+  auto* incognito_shell = CreateOffTheRecordBrowser();
+
+  EXPECT_TRUE(NavigateToURL(incognito_shell,
+                            https_server->GetURL("a.test", "/hello.html")));
+  EXPECT_EQ(EvalJs(incognito_shell, R"((async () => {
+        return await navigator.cookieDeprecationLabel.getValue()
+                       .catch(() => 'error'); })())"),
+            "error");
+}
+
 }  // namespace
 
 }  // namespace content

content/browser/storage_partition_impl.cc

@@ -1452,8 +1452,10 @@ void StoragePartitionImpl::Initialize(
       std::make_unique<BluetoothAllowedDevicesMap>();
 
   // Must be initialized before the `url_loader_factory_getter_`.
+  // Cookie deprecation traffic labels should not be sent in incognito mode.
   if (base::FeatureList::IsEnabled(
-          features::kCookieDeprecationFacilitatedTesting)) {
+          features::kCookieDeprecationFacilitatedTesting) &&
+      !is_in_memory()) {
     cookie_deprecation_label_manager_ =
         std::make_unique<CookieDeprecationLabelManagerImpl>(browser_context_);
   }

content/public/browser/content_browser_client.cc

@@ -598,14 +598,14 @@ bool ContentBrowserClient::IsPrivateAggregationDebugModeAllowed(
 
 bool ContentBrowserClient::IsCookieDeprecationLabelAllowed(
     content::BrowserContext* browser_context) {
-  return true;
+  return false;
 }
 
 bool ContentBrowserClient::IsCookieDeprecationLabelAllowedForContext(
     content::BrowserContext* browser_context,
     const url::Origin& top_frame_origin,
     const url::Origin& context_origin) {
-  return true;
+  return false;
 }
 
 bool ContentBrowserClient::CanSendSCTAuditingReport(

content/public/browser/content_browser_client.h

@@ -985,12 +985,13 @@ class CONTENT_EXPORT ContentBrowserClient {
       const url::Origin& reporting_origin);
 
   // Returns whether cookie deprecation label should be allowed for the
-  // profile.
+  // profile. Defaults to false to ensure no traffic label is sent by default.
   virtual bool IsCookieDeprecationLabelAllowed(
       content::BrowserContext* browser_context);
 
   // Returns whether cookie deprecation label should be allowed for the
-  // profile in a given context.
+  // profile in a given context. Defaults to false to ensure no traffic label
+  // is sent by default.
   virtual bool IsCookieDeprecationLabelAllowedForContext(
       content::BrowserContext* browser_context,
       const url::Origin& top_frame_origin,

content/shell/browser/shell_content_browser_client.cc

@@ -481,6 +481,18 @@ bool ShellContentBrowserClient::IsSharedStorageSelectURLAllowed(
   return true;
 }
 
+bool ShellContentBrowserClient::IsCookieDeprecationLabelAllowed(
+    content::BrowserContext* browser_context) {
+  return true;
+}
+
+bool ShellContentBrowserClient::IsCookieDeprecationLabelAllowedForContext(
+    content::BrowserContext* browser_context,
+    const url::Origin& top_frame_origin,
+    const url::Origin& context_origin) {
+  return true;
+}
+
 GeneratedCodeCacheSettings
 ShellContentBrowserClient::GetGeneratedCodeCacheSettings(
     content::BrowserContext* context) {

content/shell/browser/shell_content_browser_client.h

@@ -75,6 +75,12 @@ class ShellContentBrowserClient : public ContentBrowserClient {
       content::BrowserContext* browser_context,
       const url::Origin& top_frame_origin,
       const url::Origin& accessing_origin) override;
+  bool IsCookieDeprecationLabelAllowed(
+      content::BrowserContext* browser_context) override;
+  bool IsCookieDeprecationLabelAllowedForContext(
+      content::BrowserContext* browser_context,
+      const url::Origin& top_frame_origin,
+      const url::Origin& context_origin) override;
   GeneratedCodeCacheSettings GetGeneratedCodeCacheSettings(
       content::BrowserContext* context) override;
   base::OnceClosure SelectClientCertificate(