Start using RenderFrameProxyHost objects.

extensions/renderer/script_context.cc

 // Copyright 2014 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.
 
 #include "extensions/renderer/script_context.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
@@ skipping 170 matching lines @@
   // |document_url| (supposedly the URL of the frame).
   if (!match_about_blank || !document_url.SchemeIs(url::kAboutScheme))
     return document_url;
 
   // Non-sandboxed about:blank and about:srcdoc pages inherit their security
   // origin from their parent frame/window. So, traverse the frame/window
   // hierarchy to find the closest non-about:-page and return its URL.
   const blink::WebFrame* parent = frame;
   do {
     parent = parent->parent() ? parent->parent() : parent->opener();
-  } while (parent != NULL &&
+  } while (parent != NULL && !parent->document().isNull() &&
            GURL(parent->document().url()).SchemeIs(url::kAboutScheme));
 
-  if (parent) {
+  if (parent && !parent->document().isNull()) {
     // Only return the parent URL if the frame can access it.
     const blink::WebDocument& parent_document = parent->document();
     if (frame->document().securityOrigin().canAccess(
             parent_document.securityOrigin()))
       return parent_document.url();
   }
   return document_url;
 }
 
 ScriptContext* ScriptContext::GetContext() { return this; }
@@ skipping 33 matching lines @@
                                           v8::Handle<v8::Value> argv[]) {
   return CallFunction(function, argc, argv);
 }
 
 gin::ContextHolder* ScriptContext::GetContextHolder() {
   v8::HandleScope handle_scope(isolate());
   return gin::PerContextData::From(v8_context())->context_holder();
 }
 
 }  // namespace extensions