Send vsync timebase updates to the browser compositor

ui/gl/gl_surface_glx.h

Index: ui/gl/gl_surface_glx.h
diff --git a/ui/gl/gl_surface_glx.h b/ui/gl/gl_surface_glx.h
index 0dc235c656534eab8c1b81e90e93a4db37f716d7..20641928a1fa349d14458938277b6b5af715f68d 100644
--- a/ui/gl/gl_surface_glx.h
+++ b/ui/gl/gl_surface_glx.h
@@ -28,6 +28,7 @@ class GL_EXPORT GLSurfaceGLX : public GLSurface {
   static bool HasGLXExtension(const char* name);
   static bool IsCreateContextRobustnessSupported();
   static bool IsTextureFromPixmapSupported();
+  static bool IsOMLSyncControlSupported();
 
   virtual void* GetDisplay() OVERRIDE;
 
@@ -58,6 +59,9 @@ class GL_EXPORT NativeViewGLSurfaceGLX : public GLSurfaceGLX {
   virtual std::string GetExtensions() OVERRIDE;
   virtual void* GetConfig() OVERRIDE;
   virtual bool PostSubBuffer(int x, int y, int width, int height) OVERRIDE;
+  virtual bool GetSyncValues(int64* monotonicTime,
+                             int64* mediaStreamCounter,
+                             int64* swapBufferCounter) OVERRIDE;
 
  protected:
   NativeViewGLSurfaceGLX();