Replace RunInSeries() and RunInParallel() with CallbackSeries helper class.

media/base/serial_runner.h

+// Copyright (c) 2012 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 MEDIA_BASE_SERIAL_RUNNER_H_
+#define MEDIA_BASE_SERIAL_RUNNER_H_
+
+#include <queue>
+
+#include "base/callback.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/weak_ptr.h"
+#include "media/base/pipeline_status.h"
+
+namespace base {
+class MessageLoopProxy;
+}
+
+namespace media {
+
+// Runs a series of bound functions accepting Closures or PipelineStatusCB.
+// SerialRunner doesn't use regular Closure/PipelineStatusCBs as it late binds
+// the completion callback as the series progresses.
+class SerialRunner {
+ public:
+  typedef base::Callback<void(const base::Closure&)> BoundClosure;
+  typedef base::Callback<void(const PipelineStatusCB&)> BoundPipelineStatusCB;
+
+  // Serial queue of bound functions to run.
+  class Queue {
+   public:
+    Queue();
+    ~Queue();
+
+    void Push(const BoundClosure& bound_fn);
+    void Push(const BoundPipelineStatusCB& bound_fn);
+
+   private:
+    friend class SerialRunner;

[scherkus (not reviewing), 2012/08/03 20:44:09]

turns out this _isn't_ java!

+
+    BoundPipelineStatusCB Pop();
+    bool empty() { return bound_fns_.empty(); }

[Ami GONE FROM CHROMIUM, 2012/08/03 20:48:23]

out-of-line?

+
+    std::queue<BoundPipelineStatusCB> bound_fns_;
+  };

[scherkus (not reviewing), 2012/08/03 20:44:09]

FYI no more DISALLOW_XXX() -- I don't think I need anything else here, right?

+
+  // Executes the bound functions in series, executing |done_cb| when finished.
+  //
+  // All bound functions are executed on the thread that Run() is called on,
+  // including |done_cb|.
+  //
+  // Deleting the object will prevent execution of any unstarted bound
+  // functions, including |done_cb|.
+  static scoped_ptr<SerialRunner> Run(
+      const Queue& bound_fns, const PipelineStatusCB& done_cb);
+
+ private:
+  friend class scoped_ptr<SerialRunner>;
+
+  SerialRunner(const Queue& bound_fns, const PipelineStatusCB& done_cb);
+  ~SerialRunner();
+
+  void RunNextInSeries(PipelineStatus last_status);
+
+  base::WeakPtrFactory<SerialRunner> weak_this_;
+  scoped_refptr<base::MessageLoopProxy> message_loop_;
+  Queue bound_fns_;
+  PipelineStatusCB done_cb_;
+
+  DISALLOW_COPY_AND_ASSIGN(SerialRunner);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BASE_SERIAL_RUNNER_H_