Disable win/ash on high dpi screens

ui/gfx/win/dpi.cc

Index: ui/gfx/win/dpi.cc
diff --git a/ui/gfx/win/dpi.cc b/ui/gfx/win/dpi.cc
index acd7ee31a149ebad9a1808e1fc8a6a410b2ab5ba..33abdf63670b73a3e55707c028405e173d9948d8 100644
--- a/ui/gfx/win/dpi.cc
+++ b/ui/gfx/win/dpi.cc
@@ -36,10 +36,30 @@ float GetUnforcedDeviceScaleFactor() {
   return static_cast<float>(gfx::GetDPI().width()) /
       static_cast<float>(kDefaultDPIX);
 }
+
+float GetModernUIScaleWrapper() {
+  float result = 1.0f;
+  typedef float(WINAPI *GetModernUIScalePtr)(VOID);
+  HMODULE lib = LoadLibraryA("metro_driver.dll");
+  if (lib) {
+    GetModernUIScalePtr func =
+        reinterpret_cast<GetModernUIScalePtr>(
+        GetProcAddress(lib, "GetModernUIScale"));
+    if (func)
+      result = func();
+    FreeLibrary(lib);
+  }
+  return result;
+}
+
 }  // namespace
 
 namespace gfx {
 
+float GetModernUIScale() {
+  return GetModernUIScaleWrapper();
+}
+
 void InitDeviceScaleFactor(float scale) {
   DCHECK_NE(0.0f, scale);
   g_device_scale_factor = scale;
@@ -163,7 +183,6 @@ double GetUndocumentedDPIScale() {
   return scale;
 }
 
-
 double GetUndocumentedDPITouchScale() {
   static double scale =
       (base::win::GetVersion() < base::win::VERSION_WIN8_1) ?
@@ -171,6 +190,5 @@ double GetUndocumentedDPITouchScale() {
   return scale;
 }
 
-
 }  // namespace win
 }  // namespace gfx