RendererCompositorFrameSink should handle local surface id allocation

content/renderer/gpu/renderer_compositor_frame_sink.cc

Index: content/renderer/gpu/renderer_compositor_frame_sink.cc
diff --git a/content/renderer/gpu/renderer_compositor_frame_sink.cc b/content/renderer/gpu/renderer_compositor_frame_sink.cc
index 16ccae09e0618e338d0de11d2f4676883ea6cb42..662a9d2335104161d0c2492a30d91da40e2060de 100644
--- a/content/renderer/gpu/renderer_compositor_frame_sink.cc
+++ b/content/renderer/gpu/renderer_compositor_frame_sink.cc
@@ -109,6 +109,17 @@ void RendererCompositorFrameSink::DetachFromClient() {
 
 void RendererCompositorFrameSink::SubmitCompositorFrame(
     cc::CompositorFrame frame) {
+  float device_scale_factor = frame.metadata.device_scale_factor;
+  cc::RenderPass* root_pass = frame.render_pass_list.back().get();
+  gfx::Size frame_size = root_pass->output_rect.size();
+
+  if (!local_surface_id_.is_valid() || frame_size != last_frame_size_ ||

[Fady Samuel, 2017/03/15 12:05:48]

As discussed offline you need all the conditions checked by
DelegatedFrameHostAndroid but most only apply to Android so maybe you can put
them behind an #ifdef. Maybe a helper method would be useful here.

[Saman Sami, 2017/03/16 18:33:07]

Done.

+      device_scale_factor != last_device_scale_factor_)
+    local_surface_id_ = id_allocator_.GenerateId();
+
+  last_frame_size_ = frame_size;
+  last_device_scale_factor_ = device_scale_factor;
+
   {
     std::unique_ptr<FrameSwapMessageQueue::SendMessageScope>
         send_message_scope =
@@ -118,9 +129,9 @@ void RendererCompositorFrameSink::SubmitCompositorFrame(
     frame_swap_message_queue_->DrainMessages(&messages);
     FrameSwapMessageQueue::TransferMessages(&messages,
                                             &messages_to_deliver_with_frame);
-    Send(new ViewHostMsg_SwapCompositorFrame(routing_id_,
-                                             compositor_frame_sink_id_, frame,
-                                             messages_to_deliver_with_frame));
+    Send(new ViewHostMsg_SwapCompositorFrame(
+        routing_id_, compositor_frame_sink_id_, local_surface_id_, frame,
+        messages_to_deliver_with_frame));
     // ~send_message_scope.
   }
 }