WebDataConsumerHandle shouldn't be used on non-Oilpan threads.

Source/platform/exported/WebDataConsumerHandle.cpp

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "public/platform/WebDataConsumerHandle.h"
+
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+WebDataConsumerHandle::WebDataConsumerHandle()
+{
+    ASSERT(ThreadState::current());
+}
+
+WebDataConsumerHandle::~WebDataConsumerHandle()
+{
+    ASSERT(ThreadState::current());
+}
+
+PassOwnPtr<WebDataConsumerHandle::Reader> WebDataConsumerHandle::obtainReader(WebDataConsumerHandle::Client* client)
+{
+    ASSERT(ThreadState::current());
+    return adoptPtr(obtainReaderInternal(client));
+}
+
+} // namespace blink
+