Implement platform deleters per spec.

Source/core/storage/Storage.h

Index: Source/core/storage/Storage.h
diff --git a/Source/core/storage/Storage.h b/Source/core/storage/Storage.h
index 34e131712c6c9d90346053688f8b747eb9336e94..05da1cfe6be1dc2b12a7f2545c406584a7743b47 100644
--- a/Source/core/storage/Storage.h
+++ b/Source/core/storage/Storage.h
@@ -27,6 +27,7 @@
 #define Storage_h
 
 #include "bindings/v8/ScriptWrappable.h"
+#include "bindings/v8/V8Binding.h"
 #include "core/frame/DOMWindowProperty.h"
 #include "core/storage/StorageArea.h"
 #include "wtf/Forward.h"
@@ -57,8 +58,8 @@ public:
     String anonymousNamedGetter(const AtomicString&, ExceptionState&);
     bool anonymousNamedSetter(const AtomicString& name, const AtomicString& value, ExceptionState&);
     bool anonymousIndexedSetter(unsigned, const AtomicString&, ExceptionState&);
-    bool anonymousNamedDeleter(const AtomicString&, ExceptionState&);
-    bool anonymousIndexedDeleter(unsigned, ExceptionState&);
+    DeleteResult anonymousNamedDeleter(const AtomicString&, ExceptionState&);
+    DeleteResult anonymousIndexedDeleter(unsigned, ExceptionState&);
     void namedPropertyEnumerator(Vector<String>&, ExceptionState&);
     bool namedPropertyQuery(const AtomicString&, ExceptionState&);