Ensure that extension resources are loaded with the correct scaling applied on Windows.

ui/base/layout.cc

Index: ui/base/layout.cc
diff --git a/ui/base/layout.cc b/ui/base/layout.cc
index 2c1fb51a3952706e1f6d77a0b2f29a46c2508124..01c38f1d5414cc431705df7021de457b2b774113 100644
--- a/ui/base/layout.cc
+++ b/ui/base/layout.cc
@@ -20,6 +20,7 @@
 
 #if defined(OS_WIN)
 #include "base/win/metro.h"
+#include "ui/gfx/win/dpi.h"
 #include <Windows.h>
 #endif  // defined(OS_WIN)
 
@@ -90,7 +91,7 @@ void SetSupportedScaleFactors(
   for (std::vector<ScaleFactor>::const_iterator it =
           g_supported_scale_factors->begin();
        it != g_supported_scale_factors->end(); ++it) {
-    scales.push_back(GetImageScale(*it));
+    scales.push_back(kScaleFactorScales[*it]);
   }
   gfx::ImageSkia::SetSupportedScales(scales);
 }
@@ -117,7 +118,11 @@ ScaleFactor GetSupportedScaleFactor(float scale) {
 }
 
 float GetImageScale(ScaleFactor scale_factor) {
-  return kScaleFactorScales[scale_factor];
+#if defined(OS_WIN)
+  if (gfx::IsHighDPIEnabled())
+    return gfx::win::GetDeviceScaleFactor();
+#endif
+  return GetScaleForScaleFactor(scale_factor);
 }
 
 bool IsScaleFactorSupported(ScaleFactor scale_factor) {
@@ -144,6 +149,10 @@ ScaleFactor FindClosestScaleFactorUnsafe(float scale) {
   return closest_match;
 }
 
+float GetScaleForScaleFactor(ScaleFactor scale_factor) {
+  return kScaleFactorScales[scale_factor];
+}
+
 namespace test {
 
 ScopedSetSupportedScaleFactors::ScopedSetSupportedScaleFactors(