Split Dictionary's get and convert into DictionaryHelper.

Source/modules/serviceworkers/RegistrationOptionList.h

Index: Source/modules/serviceworkers/RegistrationOptionList.h
diff --git a/Source/modules/serviceworkers/RegistrationOptionList.h b/Source/modules/serviceworkers/RegistrationOptionList.h
index 4b204b62b3e7817e6f08156106a2ec6b09a05492..92523536b20107e48b8d0fda724b70d2cc2fdfc1 100644
--- a/Source/modules/serviceworkers/RegistrationOptionList.h
+++ b/Source/modules/serviceworkers/RegistrationOptionList.h
@@ -6,6 +6,7 @@
 #define RegistrationOptionList_h
 
 #include "bindings/core/v8/Dictionary.h"
+#include "bindings/core/v8/DictionaryHelper.h"
 
 namespace WebCore {
 
@@ -14,7 +15,7 @@ struct RegistrationOptionList  {
         : scope("/*")
     {
         // FIXME: Should be ScalarValueString. http://crbug.com/379009
-        options.get("scope", scope);
+        DictionaryHelper::get(options, "scope", scope);
     }
 
     String scope;