Disimiss JS message boxes when an interstitial is showing

chrome/browser/tab_contents/tab_contents.cc

 // Copyright (c) 2009 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/tab_contents/tab_contents.h"
 
 #include "app/l10n_util.h"
 #include "app/resource_bundle.h"
 #include "base/file_version_info.h"
 #include "base/process_util.h"
@@ skipping 1911 matching lines @@
 void TabContents::RunJavaScriptMessage(
     const std::wstring& message,
     const std::wstring& default_prompt,
     const GURL& frame_url,
     const int flags,
     IPC::Message* reply_msg,
     bool* did_suppress_message) {
   // Suppress javascript messages when requested and when inside a constrained
   // popup window (because that activates them and breaks them out of the
   // constrained window jail).
-  bool suppress_this_message = suppress_javascript_messages_;
+  // Also suppress messages when showing an interstitial. The interstitial is
+  // shown over the previous page, we don't want the hidden page dialogs to
+  // interfere with the interstitial.
+  bool suppress_this_message = suppress_javascript_messages_ ||
+                               showing_interstitial_page();
   if (delegate())
     suppress_this_message |=
         (delegate()->GetConstrainingContents(this) != this);
 
   *did_suppress_message = suppress_this_message;
 
   if (!suppress_this_message) {
     base::TimeDelta time_since_last_message(
         base::TimeTicks::Now() - last_javascript_message_dismissal_);
     bool show_suppress_checkbox = false;
@@ skipping 412 matching lines @@
       NavigationController::LoadCommittedDetails& committed_details =
           *(Details<NavigationController::LoadCommittedDetails>(details).ptr());
       ExpireInfoBars(committed_details);
       break;
     }
 
     default:
       NOTREACHED();
   }
 }