Allow non integer device scale factors in render widget

content/renderer/render_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 CONTENT_RENDERER_RENDER_WIDGET_H_
 #define CONTENT_RENDERER_RENDER_WIDGET_H_
 #pragma once
 
 #include <deque>
 #include <vector>
@@ skipping 538 matching lines @@
   // executed. Since we can have several in flight, we need to keep them in a
   // queue. Note: some SwapBuffers may not correspond to an update, in which
   // case NULL is added to the queue.
   std::deque<ViewHostMsg_UpdateRect*> updates_pending_swap_;
 
   // Properties of the screen hosting this RenderWidget instance.
   WebKit::WebScreenInfo screen_info_;
 
   // The device scale factor. This value is computed from the DPI entries in
   // |screen_info_| on some platforms, and defaults to 1 on other platforms.
-  int device_scale_factor_;
+  float device_scale_factor_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidget);
 };
 
 #endif  // CONTENT_RENDERER_RENDER_WIDGET_H_