Enable hidpi on Linux, refactor a bit on Windows to share

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index f0fc5daaf931a797407ff563eccf33fdc3414632..07974a73de2c9a52992e0af85bc23baf536df77b 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -69,6 +69,9 @@ const char kDebugPluginLoading[] = "debug-plugin-loading";
 const char kDefaultTileWidth[]              = "default-tile-width";
 const char kDefaultTileHeight[]             = "default-tile-height";
 
+// Device scale factor passed to certain processes like renderers, etc.
+const char kDeviceScaleFactor[]     = "device-scale-factor";
+
 // Disable antialiasing on 2d canvas.
 const char kDisable2dCanvasAntialiasing[]   = "disable-canvas-aa";
 
@@ -954,9 +957,6 @@ extern const char kEnableThreadedEventHandlingMac[] =
 #endif
 
 #if defined(OS_WIN)
-// Device scale factor passed to certain processes like renderers, etc.
-const char kDeviceScaleFactor[]     = "device-scale-factor";
-
 // Disable the Legacy Window which corresponds to the size of the WebContents.
 const char kDisableLegacyIntermediateWindow[] = "disable-legacy-window";