Change mojo geometry structs from using type converters to StructTraits.

ash/sysui/keyboard_ui_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 "ash/sysui/keyboard_ui_mus.h"
 
 #include "ash/keyboard/keyboard_ui_observer.h"
 #include "ash/shell.h"
 #include "ash/shell_delegate.h"
 #include "base/memory/ptr_util.h"
@@ skipping 24 matching lines @@
   keyboard_->Show();
 }
 
 bool KeyboardUIMus::IsEnabled() {
   return is_enabled_;
 }
 
 void KeyboardUIMus::OnKeyboardStateChanged(bool is_enabled,
                                            bool is_visible,
                                            uint64_t display_id,
-                                           mojo::RectPtr bounds) {
+                                           const gfx::Rect& bounds) {
   if (is_enabled_ == is_enabled)
     return;
 
   is_enabled_ = is_enabled;
   FOR_EACH_OBSERVER(KeyboardUIObserver, *observers(),
                     OnKeyboardEnabledStateChanged(is_enabled));
 }
 
 }  // namespace ash