Ensure DOMWrapperWorld always exists in all webkit_unit_tests

Source/modules/indexeddb/IDBTransactionTest.cpp

Index: Source/modules/indexeddb/IDBTransactionTest.cpp
diff --git a/Source/modules/indexeddb/IDBTransactionTest.cpp b/Source/modules/indexeddb/IDBTransactionTest.cpp
index ed13bd575b7fa0ae78156f20a6e28ef2a2a814f6..005080baa3d49286efc84c94ed0339a614f43c69 100644
--- a/Source/modules/indexeddb/IDBTransactionTest.cpp
+++ b/Source/modules/indexeddb/IDBTransactionTest.cpp
@@ -50,8 +50,7 @@ namespace {
 class IDBTransactionTest : public testing::Test {
 public:
     IDBTransactionTest()
-        : m_handleScope(v8::Isolate::GetCurrent())
-        , m_scope(v8::Context::New(v8::Isolate::GetCurrent()))
+        : m_scope(V8BindingTestScope::create(v8::Isolate::GetCurrent()))
         , m_document(Document::create())
     {
     }
@@ -62,8 +61,7 @@ public:
     }
 
 private:
-    v8::HandleScope m_handleScope;
-    v8::Context::Scope m_scope;
+    OwnPtr<V8BindingTestScope> m_scope;
     RefPtr<Document> m_document;
 };