Aura-Mus: Allocate a LocalSurfaceId on size change

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 265 matching lines @@
     // 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();
   }
   // TODO(fsamuel): If the window type is TOP_LEVEL_IN_WM or EMBED_IN_OWNER then
   // we should check if we have a cc::LocalSurfaeId ready as well. If we do,
   // then we are ready to embed.
 }
 
+const cc::LocalSurfaceId& WindowPortMus::GetLocalSurfaceId() {
+  return local_surface_id_;
+}
+
+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;
+
+  // TODO(fsamuel): If surface synchronization is enabled and the FrameSinkId
+  // is available, then immediately embed the SurfaceId. The newly generated
+  // frame by the embedder will block in the display compositor until the
+  // child submits a corresponding CompositorFrame or a deadline hits.
+
+  return local_surface_id_;
+}
+
 void WindowPortMus::SetSurfaceInfoFromServer(
     const cc::SurfaceInfo& surface_info) {
   if (surface_info_.is_valid()) {
     const cc::SurfaceId& existing_surface_id = surface_info_.id();
     const cc::SurfaceId& new_surface_id = surface_info.id();
     if (existing_surface_id.is_valid() &&
         existing_surface_id != new_surface_id) {
       // TODO(kylechar): Start return reference here?
     }
   }
@@ skipping 186 matching lines @@
       GetPropertyConverter()->GetTransportNameForPropertyKey(key);
   // TODO(sky): investigate to see if we need to compare data. In particular do
   // we ever have a case where changing a property cascades into changing the
   // same property?
   if (!RemoveChangeByTypeAndData(ServerChangeType::PROPERTY, change_data))
     window_tree_client_->OnWindowMusPropertyChanged(this, key, old_value,
                                                     std::move(data));
 }
 
 }  // namespace aura