Back PaintRecord with PaintOpBuffer instead of SkPicture

cc/BUILD.gn

Index: cc/BUILD.gn
diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index f791854447dcbdfbf87d29dc0f48e9b96eb3372c..c62ac3af82cfe3760193f015a0f0d4f659539a28 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn
@@ -647,6 +647,8 @@ cc_static_library("test_support") {
     "test/test_occlusion_tracker.h",
     "test/test_shared_bitmap_manager.cc",
     "test/test_shared_bitmap_manager.h",
+    "test/test_skcanvas.cc",
+    "test/test_skcanvas.h",
     "test/test_task_graph_runner.cc",
     "test/test_task_graph_runner.h",
     "test/test_texture.cc",
@@ -764,6 +766,7 @@ cc_test("cc_unittests") {
     "output/texture_mailbox_deleter_unittest.cc",
     "paint/discardable_image_map_unittest.cc",
     "paint/display_item_list_unittest.cc",
+    "paint/paint_op_buffer_unittest.cc",
     "quads/draw_polygon_unittest.cc",
     "quads/draw_quad_unittest.cc",
     "quads/nine_patch_generator_unittest.cc",
@@ -934,6 +937,7 @@ cc_test("cc_perftests") {
     "//cc/ipc",
     "//cc/ipc:interfaces",
     "//cc/paint",
+    "//cc/paint",
     "//cc/surfaces",
     "//cc/surfaces:surface_id",
     "//gpu",