Aura-Mus: Allocate a LocalSurfaceId on size change

ui/aura/mus/window_tree_client.cc

 // Copyright 2014 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_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 596 matching lines @@
   if (visible)
     window_tree_host->Show();
   else
     window_tree_host->Hide();
 }
 
 void WindowTreeClient::ScheduleInFlightBoundsChange(
     WindowMus* window,
     const gfx::Rect& old_bounds,
     const gfx::Rect& new_bounds) {
-  // TODO(fsamuel): Allocate a new LocalSurfaceId on size change.
   const uint32_t change_id =
       ScheduleInFlightChange(base::MakeUnique<InFlightBoundsChange>(
-          this, window, old_bounds, base::nullopt));
+          this, window, old_bounds, window->GetLocalSurfaceId()));
+  base::Optional<cc::LocalSurfaceId> local_surface_id;
+  if ((window->window_mus_type() == WindowMusType::TOP_LEVEL_IN_WM ||
+       window->window_mus_type() == WindowMusType::EMBED_IN_OWNER)) {
+    local_surface_id = window->GetOrAllocateLocalSurfaceId(new_bounds.size());
+  }
   tree_->SetWindowBounds(change_id, window->server_id(), new_bounds,
-                         base::nullopt);
+                         local_surface_id);

[sky, 2017/03/29 00:07:35]

Please add test coverage that the id sent to the server changes when the bounds
change. It would also be good to verify the revert logic works correctly for
local_surface_ids.

[Fady Samuel, 2017/03/29 22:10:14]

Done! Found a bug a fixed it. I've added two tests and modified an existing test
to verify changes to LocalSurfaceId.

This could stand to use more test coverage. I will add more in my subsequent CL.

 }
 
 void WindowTreeClient::OnWindowMusCreated(WindowMus* window) {
   if (window->server_id() != kInvalidServerId)
     return;
 
   window->set_server_id(MakeTransportId(client_id_, next_window_id_++));
   RegisterWindowMus(window);
 
   DCHECK(window_manager_delegate_ || !IsRoot(window));
@@ skipping 1286 matching lines @@
   return ScheduleInFlightChange(base::MakeUnique<InFlightCaptureChange>(
       this, capture_synchronizer_.get(), window));
 }
 
 uint32_t WindowTreeClient::CreateChangeIdForFocus(WindowMus* window) {
   return ScheduleInFlightChange(base::MakeUnique<InFlightFocusChange>(
       this, focus_synchronizer_.get(), window));
 }
 
 }  // namespace aura