Make NavigationRequest::GetNavigationEntryOffset const

There is no reason for the method not to be constant.
This clean-up was suggested in https://crrev.com/c/6180277

Change-Id: I48c9a4a30fe8e8aa650949315eaf0c6f07edbce7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6219243
Auto-Submit: Aldo Culquicondor <acondor@chromium.org>
Reviewed-by: Charlie Reis <creis@chromium.org>
Commit-Queue: Charlie Reis <creis@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1413615}

content/browser/renderer_host/navigation_request.cc

@@ -9146,7 +9146,7 @@ NavigationEntry* NavigationRequest::GetNavigationEntry() const {
       nav_entry_id_);
 }
 
-int NavigationRequest::GetNavigationEntryOffset() {
+int NavigationRequest::GetNavigationEntryOffset() const {
   return navigation_entry_offset_;
 }
 

content/browser/renderer_host/navigation_request.h

@@ -424,7 +424,7 @@ class CONTENT_EXPORT NavigationRequest
   const std::vector<std::string>& GetDnsAliases() override;
   bool IsSameProcess() override;
   NavigationEntry* GetNavigationEntry() const override;
-  int GetNavigationEntryOffset() override;
+  int GetNavigationEntryOffset() const override;
   void RegisterSubresourceOverride(
       blink::mojom::TransferrableURLLoaderPtr transferrable_loader) override;
   GlobalRenderFrameHostId GetPreviousRenderFrameHostId() override;

content/browser/renderer_host/navigation_transitions/navigation_transition_utils.cc

@@ -240,7 +240,7 @@ void RemoveScreenshotFromDestination(
 }
 
 bool ShouldSkipScreenshotWithMissReason(
-    NavigationRequest& navigation_request,
+    const NavigationRequest& navigation_request,
     std::optional<CacheHitOrMissReason>& reason) {
   if (gfx::Animation::PrefersReducedMotion()) {
     reason = CacheHitOrMissReason::kCacheMissPrefersReducedMotion;
@@ -575,7 +575,7 @@ int NavigationTransitionUtils::FindEntryIndexForNavigationTransitionID(
 }
 
 bool NavigationTransitionUtils::ShouldSkipScreenshot(
-    NavigationRequest& navigation_request) {
+    const NavigationRequest& navigation_request) {
   if (!base::FeatureList::IsEnabled(blink::features::kBackForwardTransitions)) {
     // Preserve existing behavior, where the renderer decides.
     return false;

content/browser/renderer_host/navigation_transitions/navigation_transition_utils.h

@@ -61,7 +61,7 @@ class NavigationTransitionUtils {
       NavigationControllerImpl* controller,
       NavigationTransitionData::UniqueId id);
 
-  static bool ShouldSkipScreenshot(NavigationRequest& navigation_request);
+  static bool ShouldSkipScreenshot(const NavigationRequest& navigation_request);
 
   // Used by tests to deterministically validate the memory budgeting / eviction
   // logic.

content/public/browser/navigation_handle.h

@@ -559,7 +559,7 @@ class CONTENT_EXPORT NavigationHandle : public base::SupportsUserData {
   // - History navigation to the page with subframes. The subframe
   //   navigations will return 1 here although they don't create a new
   //   navigation entry.
-  virtual int GetNavigationEntryOffset() = 0;
+  virtual int GetNavigationEntryOffset() const = 0;
 
   virtual void RegisterSubresourceOverride(
       blink::mojom::TransferrableURLLoaderPtr transferrable_loader) = 0;

content/public/test/mock_navigation_handle.h

@@ -217,7 +217,7 @@ class MockNavigationHandle : public NavigationHandle {
               (blink::mojom::TransferrableURLLoaderPtr));
   MOCK_METHOD(bool, IsSameProcess, ());
   MOCK_METHOD(NavigationEntry*, GetNavigationEntry, (), (const, override));
-  MOCK_METHOD(int, GetNavigationEntryOffset, ());
+  MOCK_METHOD(int, GetNavigationEntryOffset, (), (const, override));
   MOCK_METHOD(void,
               ForceEnableOriginTrials,
               (const std::vector<std::string>& trials));