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

content/public/common/content_switches.h

Index: content/public/common/content_switches.h
diff --git a/content/public/common/content_switches.h b/content/public/common/content_switches.h
index 0e6b87a09c0552738c6e3e50359298dce089768f..7be78a4047f63127b03e7d869ba54ad8d75e20c8 100644
--- a/content/public/common/content_switches.h
+++ b/content/public/common/content_switches.h
@@ -119,14 +119,6 @@ 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[];
-// 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[];
@@ -290,6 +282,18 @@ extern const char kEnableCarbonInterposing[];
 extern const char kDisableCoreAnimationPlugins[];
 #endif
 
+#if defined(OS_WIN)
+// This switch contains the device scale factor passed to certain processes
+// like renderers, etc.
+CONTENT_EXPORT extern const char kDeviceScaleFactor[];
+CONTENT_EXPORT extern const char kDisableLegacyIntermediateWindow[];
+CONTENT_EXPORT extern const char kEnableDirectWrite[];
+CONTENT_EXPORT extern const char kEnableHighResolutionTime[];
+// This switch will be removed when we enable the win32K lockdown process
+// mitigation.
+CONTENT_EXPORT extern const char kEnableWin32kRendererLockDown[];
+#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).