cc: Add image decode queue functionality to image manager.

cc/raster/task.h

 // Copyright 2016 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_TASK_H_
 #define CC_RASTER_TASK_H_
 
 #include <stdint.h>
 
+#include <string>
 #include <vector>
 
 #include "base/memory/ref_counted.h"
 #include "cc/base/cc_export.h"
 
 namespace cc {
 class Task;
 
 // This class provides states to manage life cycle of a task and given below is
 // how it is used by TaskGraphWorkQueue to process life cycle of a task.
@@ skipping 11 matching lines @@
 //   ┌───────────┐        ╔══════════╗
 //   │ SCHEDULED │------> ║ CANCELED ║
 //   └───────────┘        ╚══════════╝
 //         |
 //         v
 //    ┌─────────┐         ╔══════════╗
 //    │ RUNNING │-------> ║ FINISHED ║
 //    └─────────┘         ╚══════════╝
 class CC_EXPORT TaskState {
  public:
+  bool IsNew() const;
   bool IsScheduled() const;
   bool IsRunning() const;
   bool IsFinished() const;
   bool IsCanceled() const;
 
   // Functions to change the state of task. These functions should be called
   // only from TaskGraphWorkQueue where the life cycle of a task is decided or
   // from tests. These functions are not thread-safe. Caller is responsible for
   // thread safety.
   void Reset();  // Sets state to NEW.
   void DidSchedule();
   void DidStart();
   void DidFinish();
   void DidCancel();
 
+  std::string ToString() const;
+
  private:
   friend class Task;
 
   // Let only Task class create the TaskState.
   TaskState();
   ~TaskState();
 
   enum class Value : uint16_t { NEW, SCHEDULED, RUNNING, FINISHED, CANCELED };
 
   Value value_;
@@ skipping 73 matching lines @@
   Node::Vector nodes;
   Edge::Vector edges;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TaskGraph);
 };
 
 }  // namespace cc
 
 #endif  // CC_RASTER_TASK_H_