Expose WebGL extension WEBGL_debug_renderer_info to Google domains

chrome/renderer/chrome_render_view_observer.cc

 // 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.
 
 #include "chrome/renderer/chrome_render_view_observer.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 736 matching lines @@
     SendInsecureContentSignal(INSECURE_CONTENT_RUN_SWF);
 
   if (!allow_running_insecure_content_ && !allowed_per_settings) {
     content_settings_->DidNotAllowMixedScript();
     return false;
   }
 
   return true;
 }
 
+bool ChromeRenderViewObserver::allowWebGLDebugRendererInfo(WebFrame* frame) {
+  bool allowed = false;
+  Send(new ChromeViewHostMsg_IsWebGLDebugRendererInfoAllowed(
+      routing_id(),
+      GURL(frame->top()->document().securityOrigin().toString().utf8()),

[Lei Zhang, 2013/10/30 20:59:21]

Why do we use frame->top()->document() here, when other similar methods in this
file use frame->document()?

[Zhenyao Mo, 2013/10/30 21:03:00]

Ken, can you explain?  I copied this from your allowWebGL() code.

[Ken Russell (switch to Gerrit), 2013/10/30 21:35:49]

The basic idea for allowWebGL() was that we wanted to attribute GPU resets to
the outermost frame. If a frame embeds another one, then the embedding frame
should be considered "responsible" for having triggered the GPU reset. This
handles the case where a web page embeds malicious ads from a CDN.

I'm not sure whether using frame->document() would enable more use cases, such
as for example Maps embedded on some other web page. If people think that it
would, this can be changed. Otherwise it may be safer to use the style here.

+      &allowed));
+  return allowed;
+}
+
 void ChromeRenderViewObserver::didNotAllowPlugins(WebFrame* frame) {
   content_settings_->DidNotAllowPlugins();
 }
 
 void ChromeRenderViewObserver::didNotAllowScript(WebFrame* frame) {
   content_settings_->DidNotAllowScript();
 }
 
 void ChromeRenderViewObserver::OnSetIsPrerendering(bool is_prerendering) {
   if (is_prerendering) {
@@ skipping 256 matching lines @@
     WebElement element = node.to<WebElement>();
     if (!element.hasTagName(tag_name))
       continue;
     WebString value = element.getAttribute(attribute_name);
     if (value.isNull() || !LowerCaseEqualsASCII(value, "refresh"))
       continue;
     return true;
   }
   return false;
 }