scheduler: Implement task observers

content/renderer/scheduler/webthread_impl_for_scheduler.h

Index: content/renderer/scheduler/webthread_impl_for_scheduler.h
diff --git a/content/renderer/scheduler/webthread_impl_for_scheduler.h b/content/renderer/scheduler/webthread_impl_for_scheduler.h
new file mode 100644
index 0000000000000000000000000000000000000000..36bd2e2a2e7f004a57c273c180520b7b36e65522
--- /dev/null
+++ b/content/renderer/scheduler/webthread_impl_for_scheduler.h
@@ -0,0 +1,41 @@
+// 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.
+
+#ifndef CONTENT_RENDERER_SCHEDULER_WEBTHREAD_IMPL_FOR_SCHEDULER_H_
+#define CONTENT_RENDERER_SCHEDULER_WEBTHREAD_IMPL_FOR_SCHEDULER_H_
+
+#include "content/child/webthread_impl.h"
+
+#include "base/containers/scoped_ptr_hash_map.h"
+
+namespace content {
+
+class RendererScheduler;
+
+class CONTENT_EXPORT WebThreadImplForScheduler : public WebThreadBase {
+ public:
+  explicit WebThreadImplForScheduler(RendererScheduler* scheduler);
+  virtual ~WebThreadImplForScheduler();
+
+  // blink::WebThread implementation.
+  blink::PlatformThreadId threadId() const override;
+
+  // WebThreadBase implementation.
+  base::SingleThreadTaskRunner* TaskRunner() const override;
+
+ private:
+  base::MessageLoop* MessageLoop() const override;
+  void AddTaskObserverInternal(
+      base::MessageLoop::TaskObserver* observer) override;
+  void RemoveTaskObserverInternal(
+      base::MessageLoop::TaskObserver* observer) override;
+
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  RendererScheduler* scheduler_;  // Not owned.
+  blink::PlatformThreadId thread_id_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_SCHEDULER_WEBTHREAD_IMPL_FOR_SCHEDULER_H_