Deal with frame removal by content scripts

extensions/renderer/dispatcher.h

Index: extensions/renderer/dispatcher.h
diff --git a/extensions/renderer/dispatcher.h b/extensions/renderer/dispatcher.h
index 40194a06d2ab6a40e83b300a226098bcbfb8aa26..b6880066d3a3aad3f484548e083086de0a4d14f1 100644
--- a/extensions/renderer/dispatcher.h
+++ b/extensions/renderer/dispatcher.h
@@ -108,7 +108,11 @@ class Dispatcher : public content::RenderProcessObserver,
       v8::Local<v8::Context> v8_context,
       const GURL& url);
 
+  // This method is not allowed to run JavaScript code in the frame.

[Devlin, 2016/02/12 22:21:56]

Can we DCHECK this (in general for DidCreateDocumentElement) somewhere in the
blink layer? Are we already?

[robwu, 2016/02/12 22:37:13]

Blink has ScriptForbiddenScope, but it's not public.
I am reluctant to add this restriction now, because of the risk of breaking
functionality in a merge. See https://codereview.chromium.org/1642283002/#msg34

[Devlin, 2016/02/12 22:51:01]

SG.  Can we put an artfully placed TODO somewhere?

[robwu, 2016/02/12 23:24:49]

I'll add a comment at the next update to the macros at content/.

   void DidCreateDocumentElement(blink::WebLocalFrame* frame);
+  // This method may run (untrusted) JavaScript code in the frame.
+  void AfterDidCreateDocumentElement(content::RenderFrame* render_frame);
+  void AfterDidFinishDocumentLoad(content::RenderFrame* render_frame);
 
   void OnExtensionResponse(int request_id,
                            bool success,