WIP: move OffscreenCanvas into new display compositor

components/display_compositor/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 component("display_compositor") {
   sources = [
     "buffer_queue.cc",
     "buffer_queue.h",
     "compositor_overlay_candidate_validator.h",
     "display_compositor_export.h",
     "gl_helper.cc",
     "gl_helper.h",
     "gl_helper_readback_support.cc",
     "gl_helper_readback_support.h",
     "gl_helper_scaling.cc",
     "gl_helper_scaling.h",
     "gpu_compositor_frame_sink.cc",
     "gpu_compositor_frame_sink.h",
+    "gpu_compositor_frame_sink_base.cc",
+    "gpu_compositor_frame_sink_base.h",
     "gpu_compositor_frame_sink_delegate.h",
     "gpu_display_compositor_frame_sink.cc",
     "gpu_display_compositor_frame_sink.h",
     "gpu_offscreen_compositor_frame_sink.cc",
     "gpu_offscreen_compositor_frame_sink.h",
+    "offscreen_canvas_compositor_frame_sink.cc",
+    "offscreen_canvas_compositor_frame_sink.h",
   ]
 
   configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
 
   defines = [ "DISPLAY_COMPOSITOR_IMPLEMENTATION" ]
 
   deps = [
     "//base",
     "//cc",
     "//cc/ipc:interfaces",
@@ skipping 134 matching lines @@
     "//skia",
     "//testing/gmock",
     "//testing/gtest",
     "//ui/gl:test_support",
   ]
 
   data_deps = [
     "//third_party/mesa:osmesa",
   ]
 }