(not for review) Fix composited-to-non-composited corruption on Linux.

ui/gl/gl_surface_glx.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_SURFACE_GLX_H_
 #define UI_GL_GL_SURFACE_GLX_H_
 
 #include <string>
 
 #include "base/compiler_specific.h"
@@ skipping 47 matching lines @@
   virtual bool Resize(const gfx::Size& size) OVERRIDE;
   virtual bool IsOffscreen() OVERRIDE;
   virtual bool SwapBuffers() OVERRIDE;
   virtual gfx::Size GetSize() OVERRIDE;
   virtual void* GetHandle() OVERRIDE;
   virtual std::string GetExtensions() OVERRIDE;
   virtual void* GetConfig() OVERRIDE;
   virtual bool PostSubBuffer(int x, int y, int width, int height) OVERRIDE;
   virtual VSyncProvider* GetVSyncProvider() OVERRIDE;
 
+#if defined(TOOLKIT_GTK)
+  static void AcceleratedCompositingStateChange(
+      int32 surface_id, bool compositing_active);
+#endif
+
  protected:
   NativeViewGLSurfaceGLX();
   virtual ~NativeViewGLSurfaceGLX();
 
  private:
   // The handle for the drawable to make current or swap.
   gfx::AcceleratedWidget GetDrawableHandle() const;
 
   // Window passed in at creation. Always valid.
   gfx::AcceleratedWidget parent_window_;
@@ skipping 55 matching lines @@
   gfx::Size size_;
   void* config_;
   XID pbuffer_;
 
   DISALLOW_COPY_AND_ASSIGN(PbufferGLSurfaceGLX);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SURFACE_GLX_H_