Allow a main interstitial frame to act as an ExtensionMessagePort opener

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 35 matching lines @@
       WebContents* web_contents,
       bool new_navigation,
       const GURL& url,
       InterstitialPageDelegate* delegate);
 
   // Retrieves the InterstitialPage if any associated with the specified
   // |web_contents|.
   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.
+  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;
 
   // Reverts to the page showing before the interstitial.
   // Delegates should call this method when the user has chosen NOT to proceed
@@ skipping 12 matching lines @@
 
   // Sets the focus to the interstitial.
   virtual void Focus() = 0;
 
   // Gets the RenderFrameHost associated with
   // the interstitial page's main frame.
   virtual RenderFrameHost* GetMainFrame() const = 0;
 
   virtual InterstitialPageDelegate* GetDelegateForTesting() = 0;
   virtual void DontCreateViewForTesting() = 0;
+
+  virtual WebContents* web_contents() const = 0;

[Charlie Reis, 2016/01/25 21:47:38]

Style nit: We generally require CamelCase for virtual methods.

It'd be nice to avoid exposing this method if we can, since it becomes very easy
to forget that the interstitial's RFH and WebContents don't have a normal
relationship with each other (e.g., the RFH is not in the frame tree, and we
won't get the same WCO events for it).

I'm not sure if it's possible to avoid in your case or not, though.  If we do
keep it, let's put it above GetMainFrame and give some warning comments.

[robwu, 2016/01/25 22:54:41]

Done.

 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_INTERSTITIAL_PAGE_H_