Fix a race between navigation and an interstitial.

content/public/browser/interstitial_page.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_INTERSTITIAL_PAGE_H_
 #define CONTENT_PUBLIC_BROWSER_INTERSTITIAL_PAGE_H_
 
 #include "content/common/content_export.h"
 
 class GURL;
@@ skipping 30 matching lines @@
   // the interstitial was triggered by a loading a sub-resource in a page. Takes
   // ownership of |delegate|.
   //
   // Reloading the interstitial page will result in a new navigation to |url|.
   CONTENT_EXPORT static InterstitialPage* Create(
       WebContents* web_contents,
       bool new_navigation,
       const GURL& url,
       InterstitialPageDelegate* delegate);
 
-  // Retrieves the InterstitialPage if any associated with the specified
-  // |web_contents|.
+  // Returns the InterstitialPage, if any, associated with the specified
+  // |web_contents|. Note: This returns a value from the time the interstitial
+  // page has Show() called on it.
+  //
+  // Compare to WebContents::GetInterstitialPage.
   CONTENT_EXPORT static InterstitialPage* GetInterstitialPage(
       WebContents* web_contents);
 
-  // Retrieves the InterstitialPage that hosts the RenderFrameHost, or nullptr
-  // if |rfh| is not a part of any InterstitialPage.
+  // Returns the InterstitialPage that hosts the RenderFrameHost, or nullptr if
+  // |rfh| is not a part of any InterstitialPage.
   CONTENT_EXPORT static InterstitialPage* FromRenderFrameHost(
       RenderFrameHost* rfh);
 
   virtual ~InterstitialPage() {}
 
   // Shows the interstitial page in the tab.
   virtual void Show() = 0;
 
   // Hides the interstitial page.
   virtual void Hide() = 0;
@@ skipping 27 matching lines @@
   // the interstitial page's main frame.
   virtual RenderFrameHost* GetMainFrame() const = 0;
 
   virtual InterstitialPageDelegate* GetDelegateForTesting() = 0;
   virtual void DontCreateViewForTesting() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_INTERSTITIAL_PAGE_H_