Revert of Make SingleThreadProxy a SchedulerClient

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 4f379cf919f5a8744a2d4a2e92d8c6c6afeb5b32..226512fe99098a679626e525a884d1511b7fd483 100644
--- a/content/renderer/render_widget.cc
+++ b/content/renderer/render_widget.cc
@@ -393,7 +393,6 @@
       handling_event_type_(WebInputEvent::Undefined),
       ignore_ack_for_mouse_move_from_debugger_(false),
       closing_(false),
-      host_closing_(false),
       is_swapped_out_(swapped_out),
       input_method_is_active_(false),
       text_input_type_(ui::TEXT_INPUT_TYPE_NONE),
@@ -1197,8 +1196,6 @@
 }
 
 void RenderWidget::initializeLayerTreeView() {
-  DCHECK(!host_closing_);
-
   compositor_ =
       RenderWidgetCompositor::Create(this, IsThreadedCompositingEnabled());
   compositor_->setViewportSize(size_, physical_backing_size_);
@@ -1206,19 +1203,19 @@
     StartCompositor();
 }
 
-void RenderWidget::DestroyLayerTreeView() {
-  // Always send this notification to prevent new layer tree views from
-  // being created, even if one hasn't been created yet.
-  webwidget_->willCloseLayerTreeView();
-  compositor_.reset();
-}
-
 blink::WebLayerTreeView* RenderWidget::layerTreeView() {
   return compositor_.get();
 }
 
+void RenderWidget::suppressCompositorScheduling(bool enable) {
+  if (compositor_)
+    compositor_->SetSuppressScheduleComposite(enable);
+}
+
 void RenderWidget::willBeginCompositorFrame() {
   TRACE_EVENT0("gpu", "RenderWidget::willBeginCompositorFrame");
+
+  DCHECK(RenderThreadImpl::current()->compositor_message_loop_proxy().get());
 
   // The following two can result in further layout and possibly
   // enable GPU acceleration so they need to be called before any painting
@@ -1376,12 +1373,6 @@
 }
 
 void RenderWidget::DoDeferredClose() {
-  // No more compositing is possible.  This prevents shutdown races between
-  // previously posted CreateOutputSurface tasks and the host being unable to
-  // create them because the close message was handled.
-  DestroyLayerTreeView();
-  // Also prevent new compositors from being created.
-  host_closing_ = true;
   Send(new ViewHostMsg_Close(routing_id_));
 }
 
@@ -1422,7 +1413,8 @@
 void RenderWidget::Close() {
   screen_metrics_emulator_.reset();
   if (webwidget_) {
-    DestroyLayerTreeView();
+    webwidget_->willCloseLayerTreeView();
+    compositor_.reset();
     webwidget_->close();
     webwidget_ = NULL;
   }