Replace PruneAllButActive with PruneAllButVisible.

content/browser/web_contents/navigation_controller_impl.h

Index: content/browser/web_contents/navigation_controller_impl.h
diff --git a/content/browser/web_contents/navigation_controller_impl.h b/content/browser/web_contents/navigation_controller_impl.h
index 5e50d109c074ee7de230791218a22ca4c2de7fc7..5fcf3a3e430421136290111448adbb2aeff56398 100644
--- a/content/browser/web_contents/navigation_controller_impl.h
+++ b/content/browser/web_contents/navigation_controller_impl.h
@@ -87,9 +87,10 @@ class CONTENT_EXPORT NavigationControllerImpl
                                  int index) OVERRIDE;
   virtual void CopyStateFrom(
       const NavigationController& source) OVERRIDE;
-  virtual void CopyStateFromAndPrune(
+  virtual bool CopyStateFromAndPrune(
       NavigationController* source) OVERRIDE;
-  virtual void PruneAllButActive() OVERRIDE;
+  virtual bool CanPruneAllButVisible() OVERRIDE;
+  virtual bool PruneAllButVisible() OVERRIDE;
   virtual void ClearAllScreenshots() OVERRIDE;
 
   // The session storage namespace that all child RenderViews belonging to
@@ -293,10 +294,10 @@ class CONTENT_EXPORT NavigationControllerImpl
   // preparation to add another.
   void PruneOldestEntryIfFull();
 
-  // Removes all the entries except the active entry. If there is a new pending
-  // navigation it is preserved. In contrast to PruneAllButActive() this does
-  // not update the session history of the RenderView.
-  void PruneAllButActiveInternal();
+  // Removes all entries except the last committed entry.  If there is a new
+  // pending navigation it is preserved. In contrast to PruneAllButVisible()
+  // this does not update the session history of the RenderView.
+  bool PruneAllButVisibleInternal();
 
   // Returns true if the navigation is redirect.
   bool IsRedirect(const ViewHostMsg_FrameNavigate_Params& params);