Pass the device scale factor in the command line to renderer processes.

content/public/common/content_switches.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.
 
 // Defines all the "content" command-line switches.
 
 #ifndef CONTENT_PUBLIC_COMMON_CONTENT_SWITCHES_H_
 #define CONTENT_PUBLIC_COMMON_CONTENT_SWITCHES_H_
 
 #include "build/build_config.h"
@@ skipping 104 matching lines @@
 CONTENT_EXPORT extern const char kEnableFastTextAutosizing[];
 CONTENT_EXPORT extern const char kEnableFileCookies[];
 CONTENT_EXPORT extern const char kEnableGestureTapHighlight[];
 extern const char kEnableGpuClientTracing[];
 CONTENT_EXPORT extern const char kEnableGpuRasterization[];
 CONTENT_EXPORT extern const char kEnableLowResTiling[];
 CONTENT_EXPORT extern const char kEnableHighDpiCompositingForFixedPosition[];
 #if defined(OS_WIN)
 CONTENT_EXPORT extern const char kDisableLegacyIntermediateWindow[];
 CONTENT_EXPORT extern const char kEnableDirectWrite[];
+CONTENT_EXPORT extern const char kEnableHighResolutionTime[];
+// This switch contains the device scale factor passed to certain processes
+// like renderers, etc.
+CONTENT_EXPORT extern const char kUseDeviceScaleFactor[];

[sky, 2014/06/03 15:59:06]

Why the Use here? How about kDeviceScaleFactor? Also, keep alphabetical.

[ananta, 2014/06/03 19:18:13]

Done.

 // This switch will be removed when we enable the win32K lockdown process
 // mitigation.
 CONTENT_EXPORT extern const char kEnableWin32kRendererLockDown[];
-CONTENT_EXPORT extern const char kEnableHighResolutionTime[];
 #endif
 CONTENT_EXPORT extern const char kEnableImplSidePainting[];
 CONTENT_EXPORT extern const char kEnableInbandTextTracks[];
 CONTENT_EXPORT extern const char kEnableLCDText[];
 CONTENT_EXPORT extern const char kEnableLogging[];
 extern const char kEnableMemoryBenchmarking[];
 CONTENT_EXPORT extern const char kEnableOneCopy[];
 CONTENT_EXPORT extern const char kEnableOverlayFullscreenVideo[];
 CONTENT_EXPORT extern const char kDisableOverlayFullscreenVideoSubtitle[];
 CONTENT_EXPORT extern const char kEnableOverscrollNotifications[];
@@ skipping 150 matching lines @@
 extern const char kEnableCarbonInterposing[];
 extern const char kDisableCoreAnimationPlugins[];
 #endif
 
 // DON'T ADD RANDOM STUFF HERE. Put it in the main section above in
 // alphabetical order, or in one of the ifdefs (also in order in each section).
 
 }  // namespace switches
 
 #endif  // CONTENT_PUBLIC_COMMON_CONTENT_SWITCHES_H_