Add Dictionary get() method for AtomicString values and use it

Source/bindings/v8/Dictionary.cpp

Index: Source/bindings/v8/Dictionary.cpp
diff --git a/Source/bindings/v8/Dictionary.cpp b/Source/bindings/v8/Dictionary.cpp
index ffb54ecbd7a78cce41a026913cc4da4c37f914db..0571b548122428b5de038e658830635355838b18 100644
--- a/Source/bindings/v8/Dictionary.cpp
+++ b/Source/bindings/v8/Dictionary.cpp
@@ -199,7 +199,8 @@ bool Dictionary::convert(ConversionContext& context, const String& key, double&
     return true;
 }
 
-bool Dictionary::get(const String& key, String& value) const
+template<typename StringType>
+inline bool Dictionary::getStringType(const String& key, StringType& value) const
 {
     v8::Local<v8::Value> v8Value;
     if (!getKey(key, v8Value))
@@ -210,6 +211,16 @@ bool Dictionary::get(const String& key, String& value) const
     return true;
 }
 
+bool Dictionary::get(const String& key, String& value) const
+{
+    return getStringType(key, value);
+}
+
+bool Dictionary::get(const String& key, AtomicString& value) const
+{
+    return getStringType(key, value);
+}
+
 bool Dictionary::convert(ConversionContext& context, const String& key, String& value) const
 {
     ConversionContextScope scope(context);