Converts Widget::SetOpacity from char to float

ui/views/widget/widget.h

 // 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.
 
 #ifndef UI_VIEWS_WIDGET_WIDGET_H_
 #define UI_VIEWS_WIDGET_WIDGET_H_
 
 #include <map>
 #include <memory>
 #include <set>
@@ skipping 522 matching lines @@
   virtual bool IsMaximized() const;
   bool IsMinimized() const;
 
   // Accessors for fullscreen state.
   void SetFullscreen(bool fullscreen);
   bool IsFullscreen() const;
 
   // Sets the opacity of the widget. This may allow widgets behind the widget
   // in the Z-order to become visible, depending on the capabilities of the
   // underlying windowing system.
-  void SetOpacity(unsigned char opacity);
+  void SetOpacity(float opacity);
 
   // Flashes the frame of the window to draw attention to it. Currently only
   // implemented on Windows for non-Aura.
   void FlashFrame(bool flash);
 
   // Returns the View at the root of the View hierarchy contained by this
   // Widget.
   View* GetRootView();
   const View* GetRootView() const;
 
@@ skipping 419 matching lines @@
   bool movement_disabled_;
 
   ScopedObserver<ui::NativeTheme, ui::NativeThemeObserver> observer_manager_;
 
   DISALLOW_COPY_AND_ASSIGN(Widget);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WIDGET_WIDGET_H_