Update bool WindowManager::OnWmSetBounds() to match with its desirable behavior.

services/ui/demo/mus_demo.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 "services/ui/demo/mus_demo.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/time/time.h"
 #include "services/service_manager/public/cpp/connector.h"
 #include "services/service_manager/public/cpp/service_context.h"
@@ skipping 115 matching lines @@
 aura::client::CaptureClient* MusDemo::GetCaptureClient() {
   return capture_client_.get();
 }
 
 aura::PropertyConverter* MusDemo::GetPropertyConverter() {
   return property_converter_.get();
 }
 
 void MusDemo::SetWindowManagerClient(aura::WindowManagerClient* client) {}
 
-bool MusDemo::OnWmSetBounds(aura::Window* window, gfx::Rect* bounds) {
-  return true;
-}
+void MusDemo::OnWmSetBounds(aura::Window* window, const gfx::Rect& bounds) {}
 
 bool MusDemo::OnWmSetProperty(aura::Window* window,
                               const std::string& name,
                               std::unique_ptr<std::vector<uint8_t>>* new_data) {
   return true;
 }
 
 aura::Window* MusDemo::OnWmCreateTopLevelWindow(
     mojom::WindowType window_type,
     std::map<std::string, std::vector<uint8_t>>* properties) {
@@ skipping 93 matching lines @@
   gfx::ImageSkiaRep image_skia_rep(bitmap_, 1);
   gfx::ImageSkia image_skia(image_skia_rep);
   gfx::Image image(image_skia);
 
   window_delegate_->SetImage(image);
   bitmap_window_->SchedulePaintInRect(bitmap_window_->bounds());
 }
 
 }  // namespace demo
 }  // namespace aura