cc: Remove ScheduleOnOriginThread() and CompleteOnOriginThread().

cc/raster/tile_task.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 CC_RASTER_TILE_TASK_H_
 #define CC_RASTER_TILE_TASK_H_
 
 #include <vector>
 
 #include "cc/raster/task.h"
 
 namespace cc {
 class RasterBufferProvider;
 
 class CC_EXPORT TileTask : public Task {
  public:
   typedef std::vector<scoped_refptr<TileTask>> Vector;
 
+  enum class Type : uint16_t { DEFAULT, RASTER, IMAGE_DECODE, IMAGE_UPLOAD };

[reveman, 2016/05/18 16:20:31]

why are we not adding the virtual functions we need instead of this?

[prashant.n, 2016/05/18 16:45:38]

Do you mean to say - something like following?
IsRasterTask()
IsImageDecodeTask()
IsImageUploadTask()

Either way is fine, but
1. thought of having tasks know the type at the time of ctor.
2. same types can be used for perf, unit tests tasks.

[reveman, 2016/05/18 17:16:48]

No, this is not what I meant. Something seems off when we have a class with
virtual functions and we have to identify the type of instance. Why is there not
a virtual function for what we like to do differently depending on the TileTask
class? virtual void OnTaskCompleted()?

+
   const TileTask::Vector& dependencies() const { return dependencies_; }
 
+  Type type() const { return type_; }
+
   // Indicates whether this TileTask can be run at the same time as other tasks
   // in the task graph. If false, this task will be scheduled with
   // TASK_CATEGORY_NONCONCURRENT_FOREGROUND.
   bool supports_concurrent_execution() const {
     return supports_concurrent_execution_;
   }
 
-  virtual void ScheduleOnOriginThread(RasterBufferProvider* provider) = 0;
-  virtual void CompleteOnOriginThread(RasterBufferProvider* provider) = 0;
-
-  void WillSchedule();
-  void DidSchedule();
-  bool HasBeenScheduled() const;
-
-  void WillComplete();
-  void DidComplete();
-  bool HasCompleted() const;
-
  protected:
-  explicit TileTask(bool supports_concurrent_execution);
-  TileTask(bool supports_concurrent_execution, TileTask::Vector* dependencies);
+  explicit TileTask(Type type, bool supports_concurrent_execution);
+  TileTask(Type type,
+           bool supports_concurrent_execution,
+           TileTask::Vector* dependencies);
   ~TileTask() override;
 
+  const Type type_;
   const bool supports_concurrent_execution_;
   TileTask::Vector dependencies_;
-  bool did_schedule_;
-  bool did_complete_;
 };
 
 }  // namespace cc
 
 #endif  // CC_RASTER_TILE_TASK_H_