Making sure we don't take a GestureNav screenshot unless the history position changes.

content/browser/frame_host/navigator_impl.cc

Index: content/browser/frame_host/navigator_impl.cc
diff --git a/content/browser/frame_host/navigator_impl.cc b/content/browser/frame_host/navigator_impl.cc
index 64d242174b8d8586eb9678d4319e97f86b3d868e..6a06da47763076b0e23c0c459b9e2ce30440f051 100644
--- a/content/browser/frame_host/navigator_impl.cc
+++ b/content/browser/frame_host/navigator_impl.cc
@@ -426,7 +426,14 @@ void NavigatorImpl::DidNavigate(
       // calling RenderFrameHostManager::DidNavigateMainFrame, because that can
       // change WebContents::GetRenderViewHost to return the new host, instead
       // of the one that may have just been swapped out.
-      if (delegate_->CanOverscrollContent())
+      NavigationEntry* current_entry = controller_->GetLastCommittedEntry();
+      int32 current_page_id = current_entry ? current_entry->GetPageID() : -1;

[nasko, 2014/06/04 18:53:48]

nit: it will be a bit more readable with an empty line following.

[mfomitchev, 2014/06/04 19:26:20]

Done.

+      // If page id didn't change, then this is not a navigation to a new
+      // history entry or to the previous entry, and we don't need to take the
+      // screenshot.

[nasko, 2014/06/04 18:53:48]

nit: For back/forward navigations we still want to take screenshots, so what
this is trying to single out is exactly the case where the same history entry is
used. The comment as is implies that only going back to the previous history
entry or new navigations are of interest.

[mfomitchev, 2014/06/04 19:26:20]

Reworded

+      bool page_id_changed = params.page_id > 0 &&
+          params.page_id != current_page_id;
+      if (delegate_->CanOverscrollContent() && page_id_changed)
         controller_->TakeScreenshot();
 
       // Run tasks that must execute just before the commit.