Split Dictionary's get and convert into DictionaryHelper.

Source/modules/serviceworkers/ResponseInit.h

Index: Source/modules/serviceworkers/ResponseInit.h
diff --git a/Source/modules/serviceworkers/ResponseInit.h b/Source/modules/serviceworkers/ResponseInit.h
index 7cef14212341bbc2644567b4dc15f678ddb9664c..0d353749c7a54995453f73ea2e423fb7b6b900af 100644
--- a/Source/modules/serviceworkers/ResponseInit.h
+++ b/Source/modules/serviceworkers/ResponseInit.h
@@ -6,6 +6,7 @@
 #define ResponseInit_h
 
 #include "bindings/core/v8/Dictionary.h"
+#include "bindings/core/v8/DictionaryHelper.h"
 #include "modules/serviceworkers/Headers.h"
 #include "wtf/RefPtr.h"
 
@@ -21,12 +22,12 @@ struct ResponseInit {
         : status(200)
         , statusText("OK")
     {
-        options.get("status", status);
+        DictionaryHelper::get(options, "status", status);
         // FIXME: Spec uses ByteString for statusText. http://crbug.com/347426
-        options.get("statusText", statusText);
-        options.get("headers", headers);
+        DictionaryHelper::get(options, "statusText", statusText);
+        DictionaryHelper::get(options, "headers", headers);
         if (!headers) {
-            options.get("headers", headersDictionary);
+            DictionaryHelper::get(options, "headers", headersDictionary);
         }
     }