cros: Bind hangup red button on remote controller to close web dialog

ui/views/test/widget_test.h

 // Copyright 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.
 
 #ifndef UI_VIEWS_TEST_WIDGET_TEST_H_
 #define UI_VIEWS_TEST_WIDGET_TEST_H_
 
 #include "base/macros.h"
 #include "base/run_loop.h"
 #include "build/build_config.h"
@@ skipping 166 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(WidgetActivationWaiter);
 };
 
 // Use in tests to provide functionality to observe the widget passed in the
 // constructor for the widget closing event.
 class WidgetClosingObserver : public WidgetObserver {
  public:
   explicit WidgetClosingObserver(Widget* widget);
   ~WidgetClosingObserver() override;
 
+  // Returns immediately when |widget_| becomes NULL, otherwise a RunLoop is
+  // used until widget closing event is received.
+  void Wait();
+
   bool widget_closed() const { return !widget_; }
 
  private:
   // views::WidgetObserver override:
   void OnWidgetClosing(Widget* widget) override;
 
   Widget* widget_;
+  base::RunLoop run_loop_;
 
   DISALLOW_COPY_AND_ASSIGN(WidgetClosingObserver);
 };
 
 }  // namespace test
 }  // namespace views
 
 #endif  // UI_VIEWS_TEST_WIDGET_TEST_H_