Simplify calls for scale factor

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>
+#import <Cocoa/Cocoa.h>
 
 #include "base/mac/sdk_forward_declarations.h"
+#include "ui/display/display.h"
 
 namespace {
 
 float GetScaleFactorScaleForNativeView(gfx::NativeView view) {
   if (NSWindow* window = [view window]) {
     return [window backingScaleFactor];
   }
 
   NSArray* screens = [NSScreen screens];
   if (![screens count])
     return 1.0f;
 
   NSScreen* screen = [screens objectAtIndex:0];
   return [screen backingScaleFactor];
 }
 
 }  // namespace
 
 namespace ui {
 
 float GetScaleFactorForNativeView(gfx::NativeView view) {
+  if (display::Display::HasForceDeviceScaleFactor())
+    return display::Display::GetForcedDeviceScaleFactor();
   return GetScaleFactorScaleForNativeView(view);
 }
 
 }  // namespace ui