Add support for multi resolution icons

ui/base/resource/resource_bundle_mac.mm

Index: ui/base/resource/resource_bundle_mac.mm
diff --git a/ui/base/resource/resource_bundle_mac.mm b/ui/base/resource/resource_bundle_mac.mm
index 1a238a72c08d230a14f6863ce180027f2fd76086..0508177e090a0d7bddc14ff5b9bf36d8a016fb69 100644
--- a/ui/base/resource/resource_bundle_mac.mm
+++ b/ui/base/resource/resource_bundle_mac.mm
@@ -46,6 +46,11 @@ FilePath ResourceBundle::GetResourcesFilePath() {
 }
 
 // static
+FilePath ResourceBundle::GetLargeIconResourcesFilePath() {
+  return GetResourcesPakFilePath(@"theme_resources_large", nil);
+}
+
+// static
 FilePath ResourceBundle::GetLocaleFilePath(const std::string& app_locale) {
   NSString* mac_locale = base::SysUTF8ToNSString(app_locale);
 
@@ -89,6 +94,21 @@ gfx::Image& ResourceBundle::GetNativeImageNamed(int resource_id) {
 
   // Cache the converted image.
   if (ns_image.get()) {
+    // Load a high resolution version of the icon if available.
+    if (large_icon_resources_data_) {
+      scoped_refptr<RefCountedStaticMemory> large_data(
+          LoadResourceBytes(large_icon_resources_data_, resource_id));
+      if (large_data.get()) {
+        scoped_nsobject<NSData> ns_large_data(
+            [[NSData alloc] initWithBytes:large_data->front()
+                                   length:large_data->size()]);
+        NSImageRep* image_rep =
+            [NSBitmapImageRep imageRepWithData:ns_large_data];
+        if (image_rep)
+          [ns_image addRepresentation:image_rep];
+      }
+    }
+
     base::AutoLock lock(*lock_);
 
     // Another thread raced the load and has already cached the image.