Remove RenderViewHost parameter from WebContentsObserver::Did{Start|Stop}Loading.

chrome/browser/thumbnails/thumbnail_tab_helper.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/thumbnails/thumbnail_tab_helper.h"
 
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/thumbnails/thumbnail_service.h"
 #include "chrome/browser/thumbnails/thumbnail_service_factory.h"
@@ skipping 144 matching lines @@
       content::NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED,
       content::Source<RenderWidgetHost>(render_view_host));
   if (registered) {
     registrar_.Remove(
         this,
         content::NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED,
         content::Source<RenderWidgetHost>(render_view_host));
   }
 }
 
-void ThumbnailTabHelper::DidStartLoading(
-    content::RenderViewHost* render_view_host) {
+void ThumbnailTabHelper::DidStartLoading() {
   load_interrupted_ = false;
 }
 
 void ThumbnailTabHelper::NavigationStopped() {
   // This function gets called when the page loading is interrupted by the
   // stop button.
   load_interrupted_ = true;
 }
 
 void ThumbnailTabHelper::UpdateThumbnailIfNecessary(
@@ skipping 43 matching lines @@
         content::NOTIFICATION_RENDER_WIDGET_VISIBILITY_CHANGED,
         content::Source<RenderWidgetHost>(renderer));
   }
 }
 
 void ThumbnailTabHelper::WidgetHidden(RenderWidgetHost* widget) {
   if (!enabled_)
     return;
   UpdateThumbnailIfNecessary(web_contents());
 }