Update from https://crrev.com/318214

ui/gl/gl_context.h

 // 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.
 
 #ifndef UI_GL_GL_CONTEXT_H_
 #define UI_GL_GL_CONTEXT_H_
 
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/synchronization/cancellation_flag.h"
 #include "ui/gl/gl_share_group.h"
 #include "ui/gl/gl_state_restorer.h"
 #include "ui/gl/gpu_preference.h"
 
 namespace gfx {
 
 class GLSurface;
+class GPUTiming;
+class GPUTimingClient;
 class VirtualGLApi;
 struct GLVersionInfo;
 
+
 // Encapsulates an OpenGL context, hiding platform specific management.
 class GL_EXPORT GLContext : public base::RefCounted<GLContext> {
  public:
   explicit GLContext(GLShareGroup* share_group);
 
   // Initializes the GL context to be compatible with the given surface. The GL
   // context can be made with other surface's of the same type. The compatible
   // surface is only needed for certain platforms like WGL, OSMesa and GLX. It
   // should be specific for all platforms though.
   virtual bool Initialize(
       GLSurface* compatible_surface, GpuPreference gpu_preference) = 0;
 
   // Destroys the GL context.
   virtual void Destroy() = 0;
 
   // Makes the GL context and a surface current on the current thread.
   virtual bool MakeCurrent(GLSurface* surface) = 0;
 
   // Releases this GL context and surface as current on the current thread.
   virtual void ReleaseCurrent(GLSurface* surface) = 0;
 
   // Returns true if this context and surface is current. Pass a null surface
   // if the current surface is not important.
   virtual bool IsCurrent(GLSurface* surface) = 0;
 
   // Get the underlying platform specific GL context "handle".
   virtual void* GetHandle() = 0;
 
+  // Creates a GPUTimingClient class which abstracts various GPU Timing exts.
+  virtual scoped_refptr<gfx::GPUTimingClient> CreateGPUTimingClient() = 0;
+
   // Gets the GLStateRestorer for the context.
   GLStateRestorer* GetGLStateRestorer();
 
   // Sets the GLStateRestorer for the context (takes ownership).
   void SetGLStateRestorer(GLStateRestorer* state_restorer);
 
   // Set swap interval. This context must be current.
   void SetSwapInterval(int interval);
 
   // Forces the swap interval to zero (no vsync) regardless of any future values
@@ skipping 103 matching lines @@
 
   int swap_interval_;
   bool force_swap_interval_zero_;
 
   DISALLOW_COPY_AND_ASSIGN(GLContext);
 };
 
 class GL_EXPORT GLContextReal : public GLContext {
  public:
   explicit GLContextReal(GLShareGroup* share_group);
+  scoped_refptr<gfx::GPUTimingClient> CreateGPUTimingClient() override;
 
  protected:
   ~GLContextReal() override;
 
   void SetCurrent(GLSurface* surface) override;
 
  private:
+  scoped_ptr<gfx::GPUTiming> gpu_timing_;
   DISALLOW_COPY_AND_ASSIGN(GLContextReal);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_CONTEXT_H_