cc: Simplify task and its derived classes.

cc/raster/task_graph_runner.h

Index: cc/raster/task_graph_runner.h
diff --git a/cc/raster/task_graph_runner.h b/cc/raster/task_graph_runner.h
index 23094ef5a7ef3c81a6cae0fbde931c57c11efe98..ad8bc38fd8306e38feb906022e06dc2b08afa42b 100644
--- a/cc/raster/task_graph_runner.h
+++ b/cc/raster/task_graph_runner.h
@@ -16,37 +16,12 @@
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "cc/base/cc_export.h"
+#include "cc/raster/task.h"
 
 namespace cc {
 
 class TaskGraphRunner;
 
-// A task which can be run by a TaskGraphRunner. To run a Task, it should be
-// inserted into a TaskGraph, which can then be scheduled on the
-// TaskGraphRunner.
-class CC_EXPORT Task : public base::RefCountedThreadSafe<Task> {
- public:
-  typedef std::vector<scoped_refptr<Task>> Vector;
-
-  // Subclasses should implement this method. RunOnWorkerThread may be called
-  // on any thread, and subclasses are responsible for locking and thread
-  // safety.
-  virtual void RunOnWorkerThread() = 0;
-
-  void WillRun();
-  void DidRun();
-  bool HasFinishedRunning() const;
-
- protected:
-  friend class base::RefCountedThreadSafe<Task>;
-
-  Task();
-  virtual ~Task();
-
-  bool will_run_;
-  bool did_run_;
-};
-
 // A task dependency graph describes the order in which to execute a set
 // of tasks. Dependencies are represented as edges. Each node is assigned
 // a category, a priority and a run count that matches the number of