Move histograms and supporting code that don't belong in content out.

content/browser/web_contents/web_contents_impl.h

Index: content/browser/web_contents/web_contents_impl.h
===================================================================
--- content/browser/web_contents/web_contents_impl.h	(revision 207139)
+++ content/browser/web_contents/web_contents_impl.h	(working copy)
@@ -264,13 +264,7 @@
   virtual void SetOverrideEncoding(const std::string& encoding) OVERRIDE;
   virtual void ResetOverrideEncoding() OVERRIDE;
   virtual RendererPreferences* GetMutableRendererPrefs() OVERRIDE;
-  virtual void SetNewTabStartTime(const base::TimeTicks& time) OVERRIDE;
-  virtual base::TimeTicks GetNewTabStartTime() const OVERRIDE;
   virtual void Close() OVERRIDE;
-  virtual void OnCloseStarted() OVERRIDE;
-  virtual void OnCloseCanceled() OVERRIDE;
-  virtual void OnUnloadStarted() OVERRIDE;
-  virtual void OnUnloadDetachedStarted() OVERRIDE;
   virtual void SystemDragEnded() OVERRIDE;
   virtual void UserGestureDone() OVERRIDE;
   virtual void SetClosedByUserGesture(bool value) OVERRIDE;
@@ -868,18 +862,6 @@
   // Settings that get passed to the renderer process.
   RendererPreferences renderer_preferences_;
 
-  // The time that we started to create the new tab page.
-  base::TimeTicks new_tab_start_time_;
-
-  // The time that we started to close this WebContents.
-  base::TimeTicks close_start_time_;
-
-  // The time when onbeforeunload ended.
-  base::TimeTicks before_unload_end_time_;
-
-  // The time when the tab was removed from view during close.
-  base::TimeTicks unload_detached_start_time_;
-
   // The time that this tab was last selected.
   base::TimeTicks last_selected_time_;