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

services/ui/demo/mus_demo.h

 // 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.
 
 #ifndef SERVICES_UI_DEMO_MUS_DEMO_H_
 #define SERVICES_UI_DEMO_MUS_DEMO_H_
 
 #include <map>
 #include <memory>
 #include <set>
@@ skipping 33 matching lines @@
 
   // WindowTreeClientDelegate:
   void OnEmbed(Window* root) override;
   void OnEmbedRootDestroyed(Window* root) override;
   void OnLostConnection(WindowTreeClient* client) override;
   void OnPointerEventObserved(const PointerEvent& event,
                               Window* target) override;
 
   // WindowManagerDelegate:
   void SetWindowManagerClient(WindowManagerClient* client) override;
-  bool OnWmSetBounds(Window* window, gfx::Rect* bounds) override;
+  void OnWmSetBounds(Window* window, gfx::Rect* bounds) override;
   bool OnWmSetProperty(
       Window* window,
       const std::string& name,
       std::unique_ptr<std::vector<uint8_t>>* new_data) override;
   Window* OnWmCreateTopLevelWindow(
       std::map<std::string, std::vector<uint8_t>>* properties) override;
   void OnWmClientJankinessChanged(const std::set<Window*>& client_windows,
                                   bool janky) override;
   void OnWmNewDisplay(Window* window, const display::Display& display) override;
   void OnWmDisplayRemoved(ui::Window* window) override;
@@ skipping 32 matching lines @@
   // Last time a frame was drawn.
   base::TimeTicks last_draw_frame_time_;
 
   DISALLOW_COPY_AND_ASSIGN(MusDemo);
 };
 
 }  // namespace demo
 }  // namespace ui
 
 #endif  // SERVICES_UI_DEMO_MUS_DEMO_H_