Add HiDPI flag for Windows

ui/base/ui_base_switches.cc

Index: ui/base/ui_base_switches.cc
diff --git a/ui/base/ui_base_switches.cc b/ui/base/ui_base_switches.cc
index f4c3b7cbadda25a3b0697e7690394e5c97809a5c..5424578e2ade551a579d942756d9316c13539294 100644
--- a/ui/base/ui_base_switches.cc
+++ b/ui/base/ui_base_switches.cc
@@ -39,6 +39,9 @@ const char kEnableTouchEditing[] = "enable-touch-editing";
 // Enables the Views textfield on Windows.
 const char kEnableViewsTextfield[] = "enable-views-textfield";
 
+// Enables/Disables High DPI support (windows)
+const char kHighDPISupport[] = "high-dpi-support";
+
 // Overrides the device scale factor for the browser UI and the contents.
 const char kForceDeviceScaleFactor[] = "force-device-scale-factor";