cc: Merge TileTaskRunner to TileTaskWorkerPool.

cc/raster/zero_copy_tile_task_worker_pool.h

Index: cc/raster/zero_copy_tile_task_worker_pool.h
diff --git a/cc/raster/zero_copy_tile_task_worker_pool.h b/cc/raster/zero_copy_tile_task_worker_pool.h
index b5c31b1595e9dcd2c72e54d3e35797989b91a031..7a78233c5bab0e37513c7e8a63befa40e68be437 100644
--- a/cc/raster/zero_copy_tile_task_worker_pool.h
+++ b/cc/raster/zero_copy_tile_task_worker_pool.h
@@ -10,7 +10,6 @@
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/values.h"
-#include "cc/raster/tile_task_runner.h"
 #include "cc/raster/tile_task_worker_pool.h"
 
 namespace base {
@@ -23,7 +22,6 @@ namespace cc {
 class ResourceProvider;
 
 class CC_EXPORT ZeroCopyTileTaskWorkerPool : public TileTaskWorkerPool,
-                                             public TileTaskRunner,
                                              public RasterBufferProvider {
  public:
   ~ZeroCopyTileTaskWorkerPool() override;
@@ -35,9 +33,6 @@ class CC_EXPORT ZeroCopyTileTaskWorkerPool : public TileTaskWorkerPool,
       ResourceFormat preferred_tile_format);
 
   // Overridden from TileTaskWorkerPool:
-  TileTaskRunner* AsTileTaskRunner() override;
-
-  // Overridden from TileTaskRunner:
   void Shutdown() override;
   void ScheduleTasks(TaskGraph* graph) override;
   void CheckForCompletedTasks() override;