cc: Add RasterWorkerPool class.

cc/raster_worker_pool.h

Index: cc/raster_worker_pool.h
diff --git a/cc/raster_worker_pool.h b/cc/raster_worker_pool.h
new file mode 100644
index 0000000000000000000000000000000000000000..0c4d3867088e7a0c8ed5c7508935c6376ad4c031
--- /dev/null
+++ b/cc/raster_worker_pool.h
@@ -0,0 +1,98 @@
+// Copyright 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 CC_RASTER_WORKER_POOL_H_
+#define CC_RASTER_WORKER_POOL_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/threading/thread.h"
+#include "cc/rendering_stats.h"
+#include "ui/gfx/rect.h"
+
+namespace skia {
+class LazyPixelRef;
+}
+
+namespace cc {
+class PicturePileImpl;
+
+class RasterWorkerPool {
+ public:
+  explicit RasterWorkerPool(size_t num_raster_threads);
+  virtual ~RasterWorkerPool();
+
+  static scoped_ptr<RasterWorkerPool> Create(size_t num_raster_threads) {
+    return make_scoped_ptr(new RasterWorkerPool(num_raster_threads));
+  }
+
+  bool IsBusy();
+
+  void PostRasterTaskAndReply(PicturePileImpl* picture_pile,
+                              uint8* buffer,
+                              const gfx::Rect& rect,
+                              float contents_scale,
+                              const base::Closure& reply);
+  void PostImageDecodeTaskAndReply(skia::LazyPixelRef* pixel_ref,
+                                   const base::Closure& reply);
+
+  void GetRenderingStats(RenderingStats* stats);
+
+ private:
+  class Thread : public base::Thread {
+   public:
+    class Task {
+     public:
+      Task(Thread* thread);
+      ~Task();
+
+     private:
+      friend class RasterWorkerPool;
+
+      Thread* thread_;
+      RenderingStats rendering_stats_;
+
+      DISALLOW_COPY_AND_ASSIGN(Task);
+    };
+
+    Thread(const std::string name);
+    virtual ~Thread();
+
+    int num_pending_tasks() const { return num_pending_tasks_; }
+    RenderingStats& rendering_stats() { return rendering_stats_; }
+
+   private:
+    int num_pending_tasks_;
+    RenderingStats rendering_stats_;
+
+    DISALLOW_COPY_AND_ASSIGN(Thread);
+  };
+
+  class PendingTaskComparator {
+   public:
+    bool operator() (const Thread* a, const Thread* b) const {
+      return a->num_pending_tasks() < b->num_pending_tasks();
+    }
+  };
+
+  Thread::Task* CreateTask();
+  void DestroyTask(Thread::Task* task);
+
+  void OnTaskCompleted(Thread::Task* task,
+                       const base::Closure& reply);
+  void OnRasterTaskCompleted(Thread::Task* task,
+                             scoped_refptr<PicturePileImpl> picture_pile,
+                             const base::Closure& reply);
+
+  typedef std::vector<Thread*> ThreadVector;
+  ThreadVector raster_threads_;
+
+  DISALLOW_COPY_AND_ASSIGN(RasterWorkerPool);
+};
+
+}  // namespace cc
+
+#endif  // CC_RASTER_WORKER_POOL_H_