Remove calls to to-be-deprecated Persistent functions.

Source/bindings/v8/V8ValueCache.cpp

Index: Source/bindings/v8/V8ValueCache.cpp
diff --git a/Source/bindings/v8/V8ValueCache.cpp b/Source/bindings/v8/V8ValueCache.cpp
index 39157592f91dfa9b06a0f645717230c6d8d0200d..77b0cbc9ea97c0da0f9b869640326b8bd96317cf 100644
--- a/Source/bindings/v8/V8ValueCache.cpp
+++ b/Source/bindings/v8/V8ValueCache.cpp
@@ -94,7 +94,7 @@ v8::Local<v8::String> StringCache::createStringAndInsertIntoCache(StringImpl* st
     v8::Persistent<v8::String> wrapper(isolate, newString);
 
     stringImpl->ref();
-    wrapper.MarkIndependent(isolate);
+    wrapper.MarkIndependent();
     wrapper.MakeWeak(stringImpl, &makeWeakCallback);
     m_lastV8String = UnsafePersistent<v8::String>(wrapper);
     m_lastStringImpl = stringImpl;
@@ -111,7 +111,7 @@ void StringCache::makeWeakCallback(v8::Isolate* isolate, v8::Persistent<v8::Stri
     ASSERT(stringCache->m_stringCache.contains(stringImpl));
     stringCache->m_stringCache.remove(stringImpl);
     stringImpl->deref();
-    wrapper->Dispose(isolate);
+    wrapper->Dispose();
 }
 
 } // namespace WebCore