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

cc/test/test_web_graphics_context_3d.cc

 // Copyright 2011 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/test/test_web_graphics_context_3d.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 346 matching lines @@
     shared_contexts_[i]->loseContextCHROMIUM(current, other);
   shared_contexts_.clear();
 }
 
 void TestWebGraphicsContext3D::signalSyncPoint(
     unsigned sync_point,
     WebGraphicsSyncPointCallback* callback) {
   sync_point_callbacks_.push_back(callback);
 }
 
+void TestWebGraphicsContext3D::signalQuery(
+    WebKit::WebGLId query,
+    WebGraphicsSyncPointCallback* callback) {
+  sync_point_callbacks_.push_back(callback);
+}
+
 void TestWebGraphicsContext3D::setSwapBuffersCompleteCallbackCHROMIUM(
     WebGraphicsSwapBuffersCompleteCallbackCHROMIUM* callback) {
   if (support_swapbuffers_complete_callback_)
     swap_buffers_callback_ = callback;
 }
 
 void TestWebGraphicsContext3D::setMemoryAllocationChangedCallbackCHROMIUM(
     WebGraphicsMemoryAllocationChangedCallbackCHROMIUM* callback) {
   memory_allocation_changed_callback_ = callback;
 }
@@ skipping 170 matching lines @@
 
 TestWebGraphicsContext3D::Buffer::Buffer() : target(0) {}
 
 TestWebGraphicsContext3D::Buffer::~Buffer() {}
 
 TestWebGraphicsContext3D::Image::Image() {}
 
 TestWebGraphicsContext3D::Image::~Image() {}
 
 }  // namespace cc