Re-land: cc: Remove WorkerPool class and instead use TaskGraphRunner directly.

cc/resources/tile_manager.h

Index: cc/resources/tile_manager.h
diff --git a/cc/resources/tile_manager.h b/cc/resources/tile_manager.h
index 9005346faa74fda603fbdbbec2346b28df089307..11f0252cfd68c318604b6d5e122a5c0cd25b75c7 100644
--- a/cc/resources/tile_manager.h
+++ b/cc/resources/tile_manager.h
@@ -57,7 +57,7 @@ class CC_EXPORT TileManager : public RasterWorkerPoolClient,
       bool use_map_image,
       size_t max_transfer_buffer_usage_bytes,
       size_t max_raster_usage_bytes,
-      GLenum map_image_texture_target);
+      unsigned map_image_texture_target);
   virtual ~TileManager();
 
   void ManageTiles(const GlobalStateThatImpactsTilePriority& state);