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
   // to the target URL.
   // Warning: if |new_navigation| was set to true in the constructor, 'this'
   //          will be deleted when this method returns.
   virtual void DontProceed() = 0;
 
   // Delegates should call this method when the user has chosen to proceed to
   // the target URL.
   // Warning: 'this' has been deleted when this method returns.
   virtual void Proceed() = 0;
 
   // Sizes the RenderViewHost showing the actual interstitial page contents.
   virtual void SetSize(const gfx::Size& size) = 0;
 
   // Sets the focus to the interstitial.
   virtual void Focus() = 0;
 
+  // Get the WebContents in which this interstitial is shown. Warning: Frames
+  // in the intersitital are NOT visible through WebContentObservers' normal
+  // notificaions (e.g. RenderFrameDeleted). The only sensible use of this

[Charlie Reis, 2016/01/26 01:14:30]

nit: notifications

[robwu, 2016/01/26 11:29:32]

Done.

+  // returned WebContents is to add a WebContentObserver and listen for the
+  // DidAttachInterstitialPage or DidDetachInterstitialPage notifications.
+  virtual WebContents* GetUnderlyingWebContents() const = 0;

[Charlie Reis, 2016/01/26 01:14:30]

Underlying isn't a term we use elsewhere for interstitials and WebContents. 
Let's stick with GetWebContents() now that you have the nice warning comment.

[robwu, 2016/01/26 11:29:32]

Done. (I called it GetUnderlyingWebContents because the class already had an
UnderlyingContentObserver, and it seemed like a good choice for a unique name.)

[Charlie Reis, 2016/01/26 23:58:27]

Ah, I was mistaken.  But yeah, that's hidden away in the implementation file, so
I like the simpler name here in the public API.

+
   // Gets the RenderFrameHost associated with
   // 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_