Perform glReadPixels with PBOs in the gpu, if PBOs are available.

cc/resources/sync_point_helper.cc

 // Copyright 2013 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 "cc/resources/sync_point_helper.h"
 
 #include "third_party/WebKit/public/platform/WebGraphicsContext3D.h"
 
 namespace cc {
 
@@ skipping 16 matching lines @@
     WebKit::WebGraphicsContext3D* context3d,
     unsigned sync_point,
     const base::Closure& closure) {
   SignalSyncPointCallbackClass* callback_class =
       new SignalSyncPointCallbackClass(closure);
 
   // Pass ownership of the CallbackClass to WebGraphicsContext3D.
   context3d->signalSyncPoint(sync_point, callback_class);
 }
 
+void SyncPointHelper::SignalQuery(
+    WebKit::WebGraphicsContext3D* context3d,
+    WebKit::WebGLId query,
+    const base::Closure& closure) {
+  SignalSyncPointCallbackClass* callback_class =
+      new SignalSyncPointCallbackClass(closure);
+
+  // Pass ownership of the CallbackClass to WebGraphicsContext3D.
+  context3d->signalQuery(query, callback_class);
+}
+
 }  // namespace cc