Fix key navigation to cut/copy/paste zoom button on wrench menu

ui/views/controls/button/custom_button.cc

 // Copyright (c) 2012 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 "ui/views/controls/button/custom_button.h"
 
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/events/event.h"
 #include "ui/events/keycodes/keyboard_codes.h"
 #include "ui/gfx/animation/throb_animation.h"
 #include "ui/gfx/screen.h"
+#include "ui/views/controls/button/blue_button.h"
+#include "ui/views/controls/button/checkbox.h"
+#include "ui/views/controls/button/image_button.h"
+#include "ui/views/controls/button/label_button.h"
+#include "ui/views/controls/button/menu_button.h"
+#include "ui/views/controls/button/radio_button.h"
+#include "ui/views/controls/button/text_button.h"
 #include "ui/views/widget/widget.h"
 
 namespace views {
 
 // How long the hover animation takes if uninterrupted.
 static const int kHoverFadeDurationMs = 150;
 
 // static
 const char CustomButton::kViewClassName[] = "CustomButton";
 
 ////////////////////////////////////////////////////////////////////////////////
 // CustomButton, public:
 
+// static
+const CustomButton* CustomButton::AsCustomButton(const views::View* view) {
+  return AsCustomButton(const_cast<views::View*>(view));
+}
+
+CustomButton* CustomButton::AsCustomButton(views::View* view) {
+  if (view) {
+    const char* classname = view->GetClassName();

[sky, 2013/12/02 14:28:01]

check null?

[oshima, 2013/12/02 20:00:59]

I believe the expectation is this will never return NULL.
(views::GetClassName() returns "View").
I checked all other use of GetClassName() and they assume the same.

https://code.google.com/p/chromium/codesearch#search/&q=%22%3EGetClassName%22...

+    if (!strcmp(classname, Checkbox::kViewClassName) ||
+        !strcmp(classname, CustomButton::kViewClassName) ||
+        !strcmp(classname, ImageButton::kViewClassName) ||
+        !strcmp(classname, LabelButton::kViewClassName) ||
+        !strcmp(classname, RadioButton::kViewClassName) ||
+        !strcmp(classname, MenuButton::kViewClassName) ||
+        !strcmp(classname, TextButton::kViewClassName)) {
+      return static_cast<CustomButton*>(view);
+    }
+  }
+  return NULL;
+}
+
 CustomButton::~CustomButton() {
 }
 
 void CustomButton::SetState(ButtonState state) {
   if (state == state_)
     return;
 
   if (animate_on_state_change_ &&
       (!is_throbbing_ || !hover_animation_->is_animating())) {
     is_throbbing_ = false;
@@ skipping 284 matching lines @@
   if (!details.is_add && state_ != STATE_DISABLED)
     SetState(STATE_NORMAL);
 }
 
 void CustomButton::OnBlur() {
   if (IsHotTracked())
     SetState(STATE_NORMAL);
 }
 
 }  // namespace views