Update from https://crrev.com/320931

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/cancelable_callback.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 gpu {
+class GLContextVirtual;
+}  // namespace gpu
+
 namespace gfx {
 
 class GLSurface;
 class GPUTiming;
 class GPUTimingClient;
 class VirtualGLApi;
 struct GLVersionInfo;
 
 
 // Encapsulates an OpenGL context, hiding platform specific management.
@@ skipping 94 matching lines @@
   // Notify this context that |virtual_context|, that was using us, is
   // being released or destroyed.
   void OnReleaseVirtuallyCurrent(GLContext* virtual_context);
 
   // Returns the GL version string. The context must be current.
   virtual std::string GetGLVersion();
 
   // Returns the GL renderer string. The context must be current.
   virtual std::string GetGLRenderer();
 
+  // Return a callback that, when called, indicates that the state the
+  // underlying context has been changed by code outside of the command buffer,
+  // and will need to be restored.
+  virtual base::Closure GetStateWasDirtiedExternallyCallback();
+
+  // Restore the context's state if it was dirtied by an external caller.
+  virtual void RestoreStateIfDirtiedExternally();
+
  protected:
   virtual ~GLContext();
 
   // Will release the current context when going out of scope, unless canceled.
   class ScopedReleaseCurrent {
    public:
     ScopedReleaseCurrent();
     ~ScopedReleaseCurrent();
 
     void Cancel();
 
    private:
     bool canceled_;
   };
 
   // Sets the GL api to the real hardware API (vs the VirtualAPI)
   static void SetRealGLApi();
   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;
 
+  bool GetStateWasDirtiedExternally() const;
+  void SetStateWasDirtiedExternally(bool dirtied_externally);
+
  private:
   friend class base::RefCounted<GLContext>;
 
   // For GetRealCurrent.
   friend class VirtualGLApi;
+  friend class gpu::GLContextVirtual;
 
   scoped_refptr<GLShareGroup> share_group_;
   scoped_ptr<VirtualGLApi> virtual_gl_api_;
+  bool state_dirtied_externally_;
   scoped_ptr<GLStateRestorer> state_restorer_;
   scoped_ptr<GLVersionInfo> version_info_;
 
   int swap_interval_;
   bool force_swap_interval_zero_;
 
+  base::CancelableCallback<void()> state_dirtied_callback_;
+
   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_