Update from https://crrev.com/308331

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>
 
@@ skipping 58 matching lines @@
   // Get the underlying platform specific GL context "handle".
   virtual void* GetHandle() = 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.
-  virtual void SetSwapInterval(int interval) = 0;
+  void SetSwapInterval(int interval);
+
+  // Forces the swap interval to zero (no vsync) regardless of any future values
+  // passed to SetSwapInterval.
+  void ForceSwapIntervalZero(bool force);
 
   // Returns space separated list of extensions. The context must be current.
   virtual std::string GetExtensions();
 
   // Returns in bytes the total amount of GPU memory for the GPU which this
   // context is currently rendering on. Returns false if no extension exists
   // to get the exact amount of GPU memory.
   virtual bool GetTotalGpuMemory(size_t* bytes);
 
   // Indicate that it is safe to force this context to switch GPUs, since
@@ skipping 72 matching lines @@
   virtual void SetCurrent(GLSurface* surface);
 
   // Initialize function pointers to functions where the bound version depends
   // on GL version or supported extensions. Should be called immediately after
   // this context is made current.
   bool InitializeDynamicBindings();
 
   // Returns the last real (non-virtual) GLContext made current.
   static GLContext* GetRealCurrent();
 
+  virtual void OnSetSwapInterval(int interval) = 0;
+
  private:
   friend class base::RefCounted<GLContext>;
 
   // For GetRealCurrent.
   friend class VirtualGLApi;
 
   scoped_refptr<GLShareGroup> share_group_;
   scoped_ptr<VirtualGLApi> virtual_gl_api_;
   scoped_ptr<GLStateRestorer> state_restorer_;
   scoped_ptr<GLVersionInfo> version_info_;
 
   std::vector<scoped_refptr<FlushEvent> > flush_events_;
 
+  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);
 
  protected:
   ~GLContextReal() override;
 
   void SetCurrent(GLSurface* surface) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(GLContextReal);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_CONTEXT_H_