Add a WorkerScheduler and a WebThreadImplForWorker

content/child/scheduler/worker_scheduler.h

-// Copyright 2014 The Chromium Authors. All rights reserved.
+// 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_RENDERER_SCHEDULER_H_
-#define CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_
+#ifndef CONTENT_CHILD_SCHEDULER_WORKER_SCHEDULER_H_
+#define CONTENT_CHILD_SCHEDULER_WORKER_SCHEDULER_H_
 
 #include "base/message_loop/message_loop.h"
 #include "content/child/scheduler/single_thread_idle_task_runner.h"
 #include "content/common/content_export.h"
-#include "third_party/WebKit/public/web/WebInputEvent.h"
 
-namespace cc {
-struct BeginFrameArgs;
+namespace base {
+class MessageLoop;
 }
 
 namespace content {
 
-class CONTENT_EXPORT RendererScheduler {
+class CONTENT_EXPORT WorkerScheduler {
  public:
-  virtual ~RendererScheduler();
-  static scoped_ptr<RendererScheduler> Create();
+  virtual ~WorkerScheduler();
+  static scoped_ptr<WorkerScheduler> Create(base::MessageLoop* message_loop);
+
+  // Must be called before the scheduler can be used. Does any post construction
+  // initialization needed such as initiating long idle periods.

[rmcilroy, 2015/04/08 18:34:24]

nit - /s/initiating long idle periods/initializing idle period detection/ (long
idle periods are an implementation detail)

[alex clarke (OOO till 29th), 2015/04/09 10:02:37]

Done.

+  virtual void Init() = 0;
 
   // 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;
 
-  // Returns the loading task runner.  This queue is intended for tasks related
-  // to resource dispatch, foreground HTML parsing, etc...
-  virtual scoped_refptr<base::SingleThreadTaskRunner> LoadingTaskRunner() = 0;
-
-  // Called to notify about the start of an extended period where no frames
-  // need to be drawn. Must be called from the main thread.
-  virtual void BeginFrameNotExpectedSoon() = 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(
-      const blink::WebInputEvent& web_input_event) = 0;
-
-  // Tells the scheduler that the system is displaying an input animation (e.g.
-  // a fling). Called by the compositor (impl) thread.
-  virtual void DidAnimateForInputOnCompositorThread() = 0;
-
-  // Returns true if the scheduler has reason to believe that high priority work
-  // may soon arrive on the main thread, e.g., if gesture events were observed
-  // recently.
-  // Must be called from the main thread.
-  virtual bool IsHighPriorityWorkAnticipated() = 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. Note
-  // that this is a stricter condition than |IsHighPriorityWorkAnticipated|,
-  // restricted to the case where real work is pending.
-  // Must be called from the main thread.
-  virtual bool ShouldYieldForHighPriorityWork() = 0;
-
   // Returns true if a currently running idle task could exceed its deadline
   // without impacting user experience too much. This should only be used if
   // there is a task which cannot be pre-empted and is likely to take longer
   // than the largest expected idle task deadline. It should NOT be polled to
   // check whether more work can be performed on the current idle task after
   // its deadline has expired - post a new idle task for the continuation of the
   // work in this case.
   // Must be called from the main thread.

[rmcilroy, 2015/04/08 18:34:24]

'main thread' should be 'the worker's thread' right? (thoughout)

[alex clarke (OOO till 29th), 2015/04/09 10:02:37]

Done.

   virtual bool CanExceedIdleDeadlineIfRequired() const = 0;
 
   // Adds or removes a task observer from the scheduler. The observer will be
   // notified before and after every executed task. These functions can only be
   // called on the main thread.
   virtual void AddTaskObserver(
       base::MessageLoop::TaskObserver* task_observer) = 0;
   virtual void RemoveTaskObserver(
       base::MessageLoop::TaskObserver* task_observer) = 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);
+  WorkerScheduler();
+  DISALLOW_COPY_AND_ASSIGN(WorkerScheduler);
 };
 
 }  // namespace content
 
-#endif  // CONTENT_RENDERER_SCHEDULER_RENDERER_SCHEDULER_H_
+#endif  // CONTENT_CHILD_SCHEDULER_WORKER_SCHEDULER_H_