Reuse GLFenceNV when an existing CommandsCompletedQuery is reused

ui/gl/gl_fence.h

Index: ui/gl/gl_fence.h
diff --git a/ui/gl/gl_fence.h b/ui/gl/gl_fence.h
index cc25a1d735e79d13177d25c7a5280c138b994699..2f7a8772f9dff7b6b2feb146375999e1a848a5bb 100644
--- a/ui/gl/gl_fence.h
+++ b/ui/gl/gl_fence.h
@@ -25,6 +25,12 @@ class GL_EXPORT GLFence {
   // client.
   virtual void ServerWait() = 0;
 
+  // Returns true if re-setting state is supported.
+  virtual bool ResetSupported();
+
+  // Resets the fence to the original state.
+  virtual void ResetState();
+
  private:
   DISALLOW_COPY_AND_ASSIGN(GLFence);
 };