Add scale factor and 2x resources from webkit and plumb through to ContentClient.

webkit/support/platform_support_linux.cc

Index: webkit/support/platform_support_linux.cc
diff --git a/webkit/support/platform_support_linux.cc b/webkit/support/platform_support_linux.cc
index 55d851737a604f9798f632f7e6bab6e433aa68eb..e7775466b3b9e08ee9e10d7c2d78ca7599f147c5 100644
--- a/webkit/support/platform_support_linux.cc
+++ b/webkit/support/platform_support_linux.cc
@@ -46,6 +46,12 @@ string16 TestWebKitPlatformSupport::GetLocalizedString(int message_id) {
 }
 
 base::StringPiece TestWebKitPlatformSupport::GetDataResource(int resource_id) {
+  return ResourceBundle::GetSharedInstance().GetRawDataResource(resource_id);
+}
+
+base::StringPiece TestWebKitPlatformSupport::GetImageResource(
+    int resource_id,
+    float scale_factor) {
   FilePath resources_path;
   PathService::Get(base::DIR_EXE, &resources_path);
   resources_path = resources_path.Append("DumpRenderTree_resources");
@@ -72,5 +78,6 @@ base::StringPiece TestWebKitPlatformSupport::GetDataResource(int resource_id) {
     }
   }
 
+  // TODO(flackr): Pass scale_factor to ResourceBundle.
   return ResourceBundle::GetSharedInstance().GetRawDataResource(resource_id);
 }