implement getBufferSubDataAsync prototype

third_party/WebKit/Source/platform/graphics/gpu/DrawingBufferTestHelpers.h

 // Copyright 2016 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 "gpu/command_buffer/common/capabilities.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/gpu/DrawingBuffer.h"
 #include "platform/graphics/gpu/Extensions3DUtil.h"
 #include "public/platform/WebGraphicsContext3DProvider.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ skipping 62 matching lines @@
   gpu::gles2::GLES2Interface* contextGL() override { return m_gl.get(); }
   bool isSoftwareRendering() const override { return false; }
 
   // Not used by WebGL code.
   GrContext* grContext() override { return nullptr; }
   bool bindToCurrentThread() override { return false; }
   gpu::Capabilities getCapabilities() override { return gpu::Capabilities(); }
   void setLostContextCallback(const base::Closure&) {}
   void setErrorMessageCallback(
       const base::Callback<void(const char*, int32_t id)>&) {}
+  void signalQuery(uint32_t, const base::Closure&) override {}
 
  private:
   std::unique_ptr<gpu::gles2::GLES2Interface> m_gl;
 };
 
 // The target to use when binding a texture to a Chromium image.
 GLenum imageCHROMIUMTextureTarget() {
 #if OS(MACOSX)
   return GC3D_TEXTURE_RECTANGLE_ARB;
 #else
@@ skipping 140 matching lines @@
   GLbyte m_currentMailboxByte = 0;
   IntSize m_mostRecentlyProducedSize;
   bool m_createImageChromiumFail = false;
   GLuint m_currentImageId = 1;
   HashMap<GLuint, IntSize> m_textureSizes;
   HashMap<GLuint, IntSize> m_imageSizes;
   HashMap<GLuint, GLuint> m_imageToTextureMap;
 };
 
 }  // blink