GetScaleFactorForNativeView should return scale factor in float

ui/base/layout_mac.mm

 // 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/base/layout.h"
 
 #include <Cocoa/Cocoa.h>
 
 #include "base/mac/sdk_forward_declarations.h"
 
@@ skipping 13 matching lines @@
   NSScreen* screen = [screens objectAtIndex:0];
   if ([screen respondsToSelector:@selector(backingScaleFactor)])
     return [screen backingScaleFactor];
   return [screen userSpaceScaleFactor];
 }
 
 }  // namespace
 
 namespace ui {
 
-ScaleFactor GetScaleFactorForNativeView(gfx::NativeView view) {
-  return GetSupportedScaleFactor(GetScaleFactorScaleForNativeView(view));
+float GetScaleFactorForNativeView(gfx::NativeView view) {
+  return GetScaleFactorScaleForNativeView(view);
 }
 
 }  // namespace ui