Fixes for re-enabling more MSVC level 4 warnings: ui/ edition

ui/views/controls/scrollbar/native_scroll_bar.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/scrollbar/native_scroll_bar.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/message_loop/message_loop.h"
@@ skipping 39 matching lines @@
 
 void NativeScrollBar::Layout() {
   if (native_wrapper_) {
     native_wrapper_->GetView()->SetBounds(0, 0, width(), height());
     native_wrapper_->GetView()->Layout();
   }
 }
 
 void NativeScrollBar::ViewHierarchyChanged(
     const ViewHierarchyChangedDetails& details) {
-  Widget* widget;
-  if (details.is_add && !native_wrapper_ && (widget = GetWidget())) {
+  if (details.is_add && !native_wrapper_ && GetWidget()) {
     native_wrapper_ = NativeScrollBarWrapper::CreateWrapper(this);
     AddChildView(native_wrapper_->GetView());
   }
 }
 
 const char* NativeScrollBar::GetClassName() const {
   return kViewClassName;
 }
 
 // Overridden from View for keyboard UI.
@@ skipping 33 matching lines @@
 }
 
 int NativeScrollBar::GetPosition() const {
   if (!native_wrapper_)
     return 0;
   return native_wrapper_->GetPosition();
 }
 
 }  // namespace views