GetScaleFactorForNativeView should return scale factor in float

ui/base/layout.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_BASE_LAYOUT_H_
 #define UI_BASE_LAYOUT_H_
 
 #include <vector>
 
 #include "build/build_config.h"
@@ skipping 35 matching lines @@
 // On Windows high dpi, this returns the dpi scale for the display.
 UI_BASE_EXPORT float GetImageScale(ScaleFactor scale_factor);
 
 // Returns the supported ScaleFactor which most closely matches |scale|.
 // Converting from float to ScaleFactor is inefficient and should be done as
 // little as possible.
 // TODO(oshima): Make ScaleFactor a class and remove this.
 UI_BASE_EXPORT ScaleFactor GetSupportedScaleFactor(float image_scale);
 
 // Returns the ScaleFactor used by |view|.
-UI_BASE_EXPORT ScaleFactor GetScaleFactorForNativeView(gfx::NativeView view);
+UI_BASE_EXPORT float GetScaleFactorForNativeView(gfx::NativeView view);
 
 // Returns true if |scale_factor| is supported by this platform.
 UI_BASE_EXPORT bool IsScaleFactorSupported(ScaleFactor scale_factor);
 
 // Returns the scale factor closest to |scale| from the full list of factors.
 // Note that it does NOT rely on the list of supported scale factors.
 // Finding the closest match is inefficient and shouldn't be done frequently.
 UI_BASE_EXPORT ScaleFactor FindClosestScaleFactorUnsafe(float scale);
 
 // Returns the image scale for the scale factor passed in.
@@ skipping 12 matching lines @@
   std::vector<ui::ScaleFactor>* original_scale_factors_;
 
   DISALLOW_COPY_AND_ASSIGN(ScopedSetSupportedScaleFactors);
 };
 
 }  // namespace test
 
 }  // namespace ui
 
 #endif  // UI_BASE_LAYOUT_H_