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

content/public/browser/web_contents.h

Index: content/public/browser/web_contents.h
diff --git a/content/public/browser/web_contents.h b/content/public/browser/web_contents.h
index 309e264a53b6d21188d5f2d81233a22806a72870..037fef842b57e2ef679b808e28e60f4949620014 100644
--- a/content/public/browser/web_contents.h
+++ b/content/public/browser/web_contents.h
@@ -361,19 +361,10 @@ class WebContents : public PageNavigator,
   // Returns the settings which get passed to the renderer.
   virtual content::RendererPreferences* GetMutableRendererPrefs() = 0;
 
-  // Set the time when we started to create the new tab page.  This time is
-  // from before we created this WebContents.
-  virtual void SetNewTabStartTime(const base::TimeTicks& time) = 0;
-  virtual base::TimeTicks GetNewTabStartTime() const = 0;
-
   // Tells the tab to close now. The tab will take care not to close until it's
   // out of nested message loops.
   virtual void Close() = 0;
 
-  // Notification that tab closing has started.  This can be called multiple
-  // times, subsequent calls are ignored.
-  virtual void OnCloseStarted() = 0;
-
   // A render view-originated drag has ended. Informs the render view host and
   // WebContentsDelegate.
   virtual void SystemDragEnded() = 0;