Splits ToplevelWindowEventHandler into two

mash/wm/bridge/wm_window_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 "mash/wm/bridge/wm_window_mus.h"
 
 #include "ash/wm/common/container_finder.h"
 #include "ash/wm/common/window_state.h"
 #include "ash/wm/common/wm_layout_manager.h"
 #include "ash/wm/common/wm_window_observer.h"
@@ skipping 534 matching lines @@
   if (id == shell_window_id_)
     return this;
   for (mus::Window* child : window_->children()) {
     ash::wm::WmWindow* result = Get(child)->GetChildByShellWindowId(id);
     if (result)
       return result;
   }
   return nullptr;
 }
 
+void WmWindowMus::ShowResizeShadow(int component) {
+  NOTIMPLEMENTED();
+}
+
+void WmWindowMus::HideResizeShadow() {
+  NOTIMPLEMENTED();
+}
+
 void WmWindowMus::SnapToPixelBoundaryIfNecessary() {
   NOTIMPLEMENTED();
 }
 
 void WmWindowMus::AddObserver(ash::wm::WmWindowObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void WmWindowMus::RemoveObserver(ash::wm::WmWindowObserver* observer) {
   observers_.RemoveObserver(observer);
@@ skipping 42 matching lines @@
                     OnWindowBoundsChanged(this, old_bounds, new_bounds));
 }
 
 void WmWindowMus::OnWindowDestroying(mus::Window* window) {
   FOR_EACH_OBSERVER(ash::wm::WmWindowObserver, observers_,
                     OnWindowDestroying(this));
 }
 
 }  // namespace wm
 }  // namespace mash