Remove ViewHostMsg_UpdateIsDelayed

content/renderer/render_widget.cc

Index: content/renderer/render_widget.cc
diff --git a/content/renderer/render_widget.cc b/content/renderer/render_widget.cc
index 6f3af3212d31e77316d8b2e00e04096865a6f29b..2d7af62d4eab3c1126500d5460d2a78dd2f24d53 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -1260,21 +1260,6 @@ void RenderWidget::AutoResizeCompositor()  {
 void RenderWidget::didActivateCompositor() {
   TRACE_EVENT0("gpu", "RenderWidget::didActivateCompositor");
 
-#if !defined(OS_MACOSX)
-  if (!is_accelerated_compositing_active_) {
-    // When not in accelerated compositing mode, in certain cases (e.g. waiting
-    // for a resize or if no backing store) the RenderWidgetHost is blocking the
-    // browser's UI thread for some time, waiting for an UpdateRect. If we are
-    // going to switch to accelerated compositing, the GPU process may need
-    // round-trips to the browser's UI thread before finishing the frame,
-    // causing deadlocks if we delay the UpdateRect until we receive the
-    // OnSwapBuffersComplete.  So send a dummy message that will unblock the
-    // browser's UI thread. This is not necessary on Mac, because SwapBuffers
-    // now unblocks GetBackingStore on Mac.
-    Send(new ViewHostMsg_UpdateIsDelayed(routing_id_));
-  }
-#endif
-
   is_accelerated_compositing_active_ = true;
   Send(new ViewHostMsg_DidActivateAcceleratedCompositing(
       routing_id_, is_accelerated_compositing_active_));