content: Add RendererScheduler.

content/renderer/scheduler/renderer_scheduler.h

+// Copyright 2014 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_RENDERER_SCHEDULER_H_
+#define CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_
+
+#include "content/renderer/scheduler/single_thread_idle_task_runner.h"
+#include "content/renderer/scheduler/task_queue_manager.h"
+
+namespace cc {
+struct BeginFrameArgs;
+}
+
+namespace content {
+
+class CONTENT_EXPORT RendererScheduler {
+ public:
+  virtual ~RendererScheduler();
+  static scoped_ptr<RendererScheduler> Create();
+
+  // Returns the default task runner.
+  virtual scoped_refptr<base::SingleThreadTaskRunner> DefaultTaskRunner() = 0;
+
+  // Returns the compositor task runner.
+  virtual scoped_refptr<base::SingleThreadTaskRunner>
+  CompositorTaskRunner() = 0;
+
+  // Returns the idle task runner. Tasks posted to this runner may be reordered
+  // relative to other task types and may be starved for an arbitrarily long
+  // time if no idle time is available.
+  virtual scoped_refptr<SingleThreadIdleTaskRunner> IdleTaskRunner() = 0;
+
+  // Called to notify about the start of a new frame.  Must be called from the
+  // main thread.
+  virtual void WillBeginFrame(const cc::BeginFrameArgs& args) = 0;
+
+  // Called to notify that a previously begun frame was committed. Must be
+  // called from the main thread.
+  virtual void DidCommitFrameToCompositor() = 0;
+
+  // Tells the scheduler that the system received an input event. Called by the
+  // compositor (impl) thread.
+  virtual void DidReceiveInputEventOnCompositorThread() = 0;
+
+  // Returns true if there is high priority work pending on the main thread
+  // and the caller should yield to let the scheduler service that work.
+  // Must be called from the main thread.
+  virtual bool ShouldYieldForHighPriorityWork() = 0;
+
+  // Shuts down the scheduler by dropping any remaining pending work in the work
+  // queues. After this call any work posted to the task runners will be
+  // silently dropped.
+  virtual void Shutdown() = 0;
+
+ protected:
+  RendererScheduler();
+  DISALLOW_COPY_AND_ASSIGN(RendererScheduler);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_