Add WebContents source to methods in WebContentsDelegate

chrome/browser/prerender/prerender_manager.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/prerender/prerender_manager.h"
 
 #include <algorithm>
 #include <functional>
 #include <string>
 #include <vector>
@@ skipping 173 matching lines @@
   void CloseContents(WebContents* source) override {
     DCHECK_EQ(tab_, source);
     ScheduleWebContentsForDeletion(false);
   }
 
   void SwappedOut(WebContents* source) override {
     DCHECK_EQ(tab_, source);
     ScheduleWebContentsForDeletion(false);
   }
 
-  bool ShouldSuppressDialogs() override {
+  bool ShouldSuppressDialogs(WebContents* source) override {
     // Use this as a proxy for getting statistics on how often we fail to honor
     // the beforeunload event.
+    DCHECK_EQ(tab_, source);
     suppressed_dialog_ = true;
     return true;
   }
 
  private:
   static const int kDeleteWithExtremePrejudiceSeconds = 3;
 
   void ScheduleWebContentsForDeletion(bool timeout) {
     UMA_HISTOGRAM_BOOLEAN("Prerender.TabContentsDeleterTimeout", timeout);
     UMA_HISTOGRAM_BOOLEAN("Prerender.TabContentsDeleterSuppressedDialog",
@@ skipping 1690 matching lines @@
     content::RenderProcessHost* host) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   prerender_process_hosts_.erase(host);
   BrowserThread::PostTask(
       BrowserThread::IO, FROM_HERE,
       base::Bind(&PrerenderTracker::RemovePrerenderCookieStoreOnIOThread,
                  base::Unretained(prerender_tracker()), host->GetID(), false));
 }
 
 }  // namespace prerender