TaskGraphRunner refactor

cc/BUILD.gn

Index: cc/BUILD.gn
diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index 2ff2593027f8bae00a85bbea5d9147a4f3ca44bb..1e592623ea9a142b44126ed8fb007169ea5e61e7 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn
@@ -359,8 +359,14 @@ component("cc") {
     "raster/raster_buffer.h",
     "raster/scoped_gpu_raster.cc",
     "raster/scoped_gpu_raster.h",
+    "raster/single_thread_task_graph_runner.cc",
+    "raster/single_thread_task_graph_runner.h",
+    "raster/synchronous_task_graph_runner.cc",
+    "raster/synchronous_task_graph_runner.h",
     "raster/task_graph_runner.cc",
     "raster/task_graph_runner.h",
+    "raster/task_graph_work_queue.cc",
+    "raster/task_graph_work_queue.h",
     "raster/texture_compressor.cc",
     "raster/texture_compressor.h",
     "raster/texture_compressor_etc1.cc",
@@ -645,6 +651,8 @@ source_set("test_support") {
     "test/surface_aggregator_test_helpers.h",
     "test/surface_hittest_test_helpers.cc",
     "test/surface_hittest_test_helpers.h",
+    "test/task_graph_runner_test_template.cc",
+    "test/task_graph_runner_test_template.h",
     "test/test_context_provider.cc",
     "test/test_context_provider.h",
     "test/test_context_support.cc",
@@ -798,7 +806,8 @@ test("cc_unittests") {
     "quads/draw_quad_unittest.cc",
     "quads/render_pass_unittest.cc",
     "raster/scoped_gpu_raster_unittest.cc",
-    "raster/task_graph_runner_unittest.cc",
+    "raster/single_thread_task_graph_runner_unittest.cc",
+    "raster/synchronous_task_graph_runner_unittest.cc",
     "raster/texture_compressor_etc1_unittest.cc",
     "raster/tile_task_worker_pool_unittest.cc",
     "resources/platform_color_unittest.cc",