Expose WebGL extension WEBGL_debug_renderer_info to Google domains

chrome/renderer/chrome_render_view_observer.cc

Index: chrome/renderer/chrome_render_view_observer.cc
diff --git a/chrome/renderer/chrome_render_view_observer.cc b/chrome/renderer/chrome_render_view_observer.cc
index 6fcdf2a3dbb6b94d89ee527b332932f7cb016216..239af55a8586f0e81a7bcf8aad78e0431a0f1d15 100644
--- a/chrome/renderer/chrome_render_view_observer.cc
+++ b/chrome/renderer/chrome_render_view_observer.cc
@@ -754,6 +754,15 @@ bool ChromeRenderViewObserver::allowRunningInsecureContent(
   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();
 }