Deal with frame removal by content scripts

content/public/renderer/content_renderer_client.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_RENDERER_CONTENT_RENDERER_CLIENT_H_
 #define CONTENT_PUBLIC_RENDERER_CONTENT_RENDERER_CLIENT_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 287 matching lines @@
   // Allows an embedder to provide a blink::WebAppBannerClient.
   virtual scoped_ptr<blink::WebAppBannerClient> CreateAppBannerClient(
       RenderFrame* render_frame);
 
   // Gives the embedder a chance to add properties to the context menu.
   // Currently only called when the context menu is for an image.
   virtual void AddImageContextMenuProperties(
       const blink::WebURLResponse& response,
       std::map<std::string, std::string>* properties) {}
 
+  // Notifies that a document element has been inserted in the frame's document.
+  // This may be called multiple times for the same document. This method may
+  // invalidate the frame, which resets the weak pointer.
+  virtual void AfterDidCreateDocumentElement(

[nasko, 2016/02/11 16:49:01]

Why the "After" prefix? It is called from DidCreateDocumentElement, right?

I also wonder if there is a way to avoid using a WeakPtr as an argument to this
method.

[robwu, 2016/02/11 17:51:08]

It is called after the DidCreateDocumentElement observers have been notified.
It is possible, by inheriting from SupportsWeakPtr<RenderFrame> instead of
making the WeakPtrFactory a member of RenderFrame. Callees can then use
render_frame->AsWeakPtr().

+      const base::WeakPtr<RenderFrame>& render_frame) {}
+
+  // Notifies that the DOM is ready in the frame's document.
+  // This method may invalidate the frame, which resets the weak pointer.
+  virtual void AfterDidFinishDocumentLoad(
+      const base::WeakPtr<RenderFrame>& render_frame) {}
+
   // Notifies that a service worker context has been created. This function
   // is called from the worker thread.
   virtual void DidInitializeServiceWorkerContextOnWorkerThread(
       v8::Local<v8::Context> context,
       const GURL& url) {}
 
   // Notifies that a service worker context will be destroyed. This function
   // is called from the worker thread.
   virtual void WillDestroyServiceWorkerContextOnWorkerThread(
       v8::Local<v8::Context> context,
       const GURL& url) {}
 
   // Whether this renderer should enforce preferences related to the WebRTC
   // routing logic, i.e. allowing multiple routes and non-proxied UDP.
   virtual bool ShouldEnforceWebRTCRoutingPreferences();
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_RENDERER_CONTENT_RENDERER_CLIENT_H_