Revert 258077 "Remove PrepareForShutdown"

trunk/src/mojo/examples/aura_demo/window_tree_host_mojo.cc

 // Copyright (c) 2013 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 "mojo/examples/aura_demo/window_tree_host_mojo.h"
 
 #include "mojo/examples/aura_demo/demo_context_factory.h"
 #include "mojo/public/bindings/allocation_scope.h"
 #include "mojo/public/gles2/gles2.h"
 #include "mojo/services/native_viewport/geometry_conversions.h"
@@ skipping 110 matching lines @@
 
 void WindowTreeHostMojo::PostNativeEvent(
     const base::NativeEvent& native_event) {
   NOTIMPLEMENTED();
 }
 
 void WindowTreeHostMojo::OnDeviceScaleFactorChanged(float device_scale_factor) {
   NOTIMPLEMENTED();
 }
 
+void WindowTreeHostMojo::PrepareForShutdown() {
+  NOTIMPLEMENTED();
+}
+
 void WindowTreeHostMojo::SetCursorNative(gfx::NativeCursor cursor) {
   NOTIMPLEMENTED();
 }
 
 void WindowTreeHostMojo::MoveCursorToNative(const gfx::Point& location) {
   NOTIMPLEMENTED();
 }
 
 void WindowTreeHostMojo::OnCursorVisibilityChangedNative(bool show) {
   NOTIMPLEMENTED();
@@ skipping 50 matching lines @@
           event.flags(), event.key_data().is_char());
       SendEventToProcessor(&ev);
       break;
     }
     // TODO(beng): touch, etc.
   }
 };
 
 }  // namespace examples
 }  // namespace mojo