Introduce painted-device-scale-factor and use it when --enable-use-zoom-for-dsf is specified.

chrome/browser/chromeos/login/chrome_restart_request.cc

 // Copyright 2013 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 "chrome/browser/chromeos/login/chrome_restart_request.h"
 
 #include <vector>
 
 #include "ash/ash_switches.h"
 #include "base/base_switches.h"
@@ skipping 95 matching lines @@
     ::switches::kEnableGpuRasterization,
     ::switches::kEnableImageColorProfiles,
     ::switches::kEnableLogging,
     ::switches::kEnableLowResTiling,
     ::switches::kEnablePartialRaster,
     ::switches::kEnablePinch,
     ::switches::kEnablePreferCompositingToLCDText,
     ::switches::kEnableRGBA4444Textures,
     ::switches::kEnableSlimmingPaintV2,
     ::switches::kEnableTouchDragDrop,
+    ::switches::kEnableUseZoomForDSF,
     ::switches::kEnableViewport,
     ::switches::kEnableZeroCopy,
 #if defined(USE_OZONE)
     ::switches::kExtraTouchNoiseFiltering,
 #endif
     ::switches::kMainFrameResizesAreOrientationChanges,
     ::switches::kForceDeviceScaleFactor,
     ::switches::kForceGpuRasterization,
     ::switches::kGpuRasterizationMSAASampleCount,
     ::switches::kGpuStartupDialog,
@@ skipping 223 matching lines @@
     // Relaunch chrome without session manager on dev box.
     ReLaunch(command_line);
     return;
   }
 
   // ChromeRestartRequest deletes itself after request sent to session manager.
   (new ChromeRestartRequest(command_line.argv()))->Start();
 }
 
 }  // namespace chromeos