Enable inspector tests disabled when dart:html was switched to JS interop.

Source/bindings/core/dart/DartHandleProxy.cpp

Index: Source/bindings/core/dart/DartHandleProxy.cpp
diff --git a/Source/bindings/core/dart/DartHandleProxy.cpp b/Source/bindings/core/dart/DartHandleProxy.cpp
index 89ba858b2708b6fada2ef9d02fe73923c15f1ee9..f9015aa63660ec275f14792383416499f1773c9c 100644
--- a/Source/bindings/core/dart/DartHandleProxy.cpp
+++ b/Source/bindings/core/dart/DartHandleProxy.cpp
@@ -63,8 +63,12 @@ DartPersistentValue* DartHandleProxy::readPointerFromProxy(v8::Handle<v8::Value>
 
 bool DartHandleProxy::isDartProxy(v8::Handle<v8::Value> value)
 {
+    return isDartProxy(value, v8::Isolate::GetCurrent());
+}
+
+bool DartHandleProxy::isDartProxy(v8::Handle<v8::Value> value, v8::Isolate* v8Isolate)
+{
     if (!value.IsEmpty() && value->IsObject()) {
-        v8::Isolate* v8Isolate = v8::Isolate::GetCurrent();
         v8::Local<v8::Value> hiddenValue = value.As<v8::Object>()->GetHiddenValue(v8::String::NewFromUtf8(v8Isolate, "dartProxy"));
         return *hiddenValue && hiddenValue->IsBoolean();
     }