Frames received after guest detaches should be displayed.

content/browser/frame_host/render_widget_host_view_guest.cc

Index: content/browser/frame_host/render_widget_host_view_guest.cc
diff --git a/content/browser/frame_host/render_widget_host_view_guest.cc b/content/browser/frame_host/render_widget_host_view_guest.cc
index 66ef61369b3a1f3093b8604118eecaeeb5508bd3..c22ce75b5b8a7be4453b09c72ca90610e63f3256 100644
--- a/content/browser/frame_host/render_widget_host_view_guest.cc
+++ b/content/browser/frame_host/render_widget_host_view_guest.cc
@@ -207,11 +207,10 @@ void RenderWidgetHostViewGuest::SetTooltipText(
 void RenderWidgetHostViewGuest::OnSwapCompositorFrame(
     uint32_t output_surface_id,
     scoped_ptr<cc::CompositorFrame> frame) {
-  if (!guest_ || !guest_->attached()) {
-    // We shouldn't hang on to a surface while we are detached.
-    ClearCompositorSurfaceIfNecessary();
-    return;
-  }
+  // If after detaching we are sent a frame, we should finish processing it, and
+  // then we should clear the surface so that we are not holding resources we
+  // no longer need.
+  bool should_clear_compositor_surface_on_exit = !guest_ || !guest_->attached();

[wjmaclean, 2016/03/08 16:13:06]

We don't actually need to declare a var for this if we don't want to, rather we
can just check !guest_ || !guest_->attached() in the if-statement at the end.

 
   last_scroll_offset_ = frame->metadata.root_scroll_offset;
 
@@ -266,6 +265,9 @@ void RenderWidgetHostViewGuest::OnSwapCompositorFrame(
                                           ack_callback);
 
   ProcessFrameSwappedCallbacks();
+
+  if (should_clear_compositor_surface_on_exit)
+    ClearCompositorSurfaceIfNecessary();
 }
 
 bool RenderWidgetHostViewGuest::OnMessageReceived(const IPC::Message& msg) {