Only send the FrameSinkId to client when it is necessary

ui/aura/mus/window_port_mus.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/aura/mus/window_port_mus.h"
 
 #include "base/memory/ptr_util.h"
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/transient_window_client.h"
 #include "ui/aura/mus/client_surface_embedder.h"
@@ skipping 75 matching lines @@
   window_tree_client_->SetCanAcceptDrops(this, can_accept_drops);
 }
 
 void WindowPortMus::Embed(
     ui::mojom::WindowTreeClientPtr client,
     uint32_t flags,
     const ui::mojom::WindowTree::EmbedCallback& callback) {
   window_tree_client_->Embed(window_, std::move(client), flags, callback);
 }
 
-void WindowPortMus::RequestCompositorFrameSink(
+std::unique_ptr<cc::CompositorFrameSink>
+WindowPortMus::RequestCompositorFrameSink(
     scoped_refptr<cc::ContextProvider> context_provider,
-    gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
-    const CompositorFrameSinkCallback& callback) {
-  DCHECK(pending_compositor_frame_sink_request_.is_null());
-  // If we haven't received a FrameSinkId from the window server yet then we
-  // bind the parameters to a closure that will be called once the FrameSinkId
-  // is available.
-  if (!frame_sink_id_.is_valid()) {
-    pending_compositor_frame_sink_request_ =
-        base::Bind(&WindowPortMus::RequestCompositorFrameSinkInternal,
-                   base::Unretained(this), std::move(context_provider),
-                   gpu_memory_buffer_manager, callback);
-    return;
-  }
-
-  RequestCompositorFrameSinkInternal(std::move(context_provider),
-                                     gpu_memory_buffer_manager, callback);
-}
-
-void WindowPortMus::RequestCompositorFrameSinkInternal(
-    scoped_refptr<cc::ContextProvider> context_provider,
-    gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager,
-    const CompositorFrameSinkCallback& callback) {
-  DCHECK(frame_sink_id_.is_valid());
+    gpu::GpuMemoryBufferManager* gpu_memory_buffer_manager) {
   std::unique_ptr<ui::ClientCompositorFrameSinkBinding>
       compositor_frame_sink_binding;
   std::unique_ptr<ui::ClientCompositorFrameSink> compositor_frame_sink =
       ui::ClientCompositorFrameSink::Create(
-          frame_sink_id_, std::move(context_provider),
-          gpu_memory_buffer_manager, &compositor_frame_sink_binding);
+          std::move(context_provider), gpu_memory_buffer_manager,
+          &compositor_frame_sink_binding,
+          window_tree_client_->enable_surface_synchronization_);
   AttachCompositorFrameSink(std::move(compositor_frame_sink_binding));
-  callback.Run(std::move(compositor_frame_sink));
+  return std::move(compositor_frame_sink);
 }
 
 void WindowPortMus::AttachCompositorFrameSink(
     std::unique_ptr<ui::ClientCompositorFrameSinkBinding>
         compositor_frame_sink_binding) {
   window_tree_client_->AttachCompositorFrameSink(
       server_id(), compositor_frame_sink_binding->TakeFrameSinkRequest(),
       mojo::MakeProxy(compositor_frame_sink_binding->TakeFrameSinkClient()));
 }
 
@@ skipping 142 matching lines @@
     const std::vector<uint8_t>* property_data) {
   ServerChangeData data;
   data.property_name = property_name;
   ScopedServerChange change(this, ServerChangeType::PROPERTY, data);
   GetPropertyConverter()->SetPropertyFromTransportValue(window_, property_name,
                                                         property_data);
 }
 
 void WindowPortMus::SetFrameSinkIdFromServer(
     const cc::FrameSinkId& frame_sink_id) {
+  DCHECK(window_mus_type() == WindowMusType::TOP_LEVEL_IN_WM ||
+         window_mus_type() == WindowMusType::EMBED_IN_OWNER);
   frame_sink_id_ = frame_sink_id;
-  if (!pending_compositor_frame_sink_request_.is_null()) {
-    // TOP_LEVEL_IN_WM, and EMBED_IN_OWNER windows should not be requesting
-    // CompositorFrameSinks.
-    DCHECK_NE(WindowMusType::TOP_LEVEL_IN_WM, window_mus_type());
-    DCHECK_NE(WindowMusType::EMBED_IN_OWNER, window_mus_type());
-    base::ResetAndReturn(&pending_compositor_frame_sink_request_).Run();
-    return;
-  }
   UpdatePrimarySurfaceInfo();
 }
 
 const cc::LocalSurfaceId& WindowPortMus::GetOrAllocateLocalSurfaceId(
     const gfx::Size& surface_size) {
   if (last_surface_size_ == surface_size && local_surface_id_.is_valid())
     return local_surface_id_;
 
   local_surface_id_ = local_surface_id_allocator_.GenerateId();
   last_surface_size_ = surface_size;
@@ skipping 244 matching lines @@
   if (!client_surface_embedder_) {
     client_surface_embedder_ = base::MakeUnique<ClientSurfaceEmbedder>(
         window_, window_tree_client_->normal_client_area_insets_);
   }
 
   client_surface_embedder_->SetPrimarySurfaceInfo(primary_surface_info_);
   client_surface_embedder_->SetFallbackSurfaceInfo(fallback_surface_info_);
 }
 
 }  // namespace aura