Consolidate OutputSurface constructors into GL vs Vulkan.

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",
@@ skipping 39 matching lines @@
   if (use_ozone) {
     sources += [
       "compositor_overlay_candidate_validator_ozone.cc",
       "compositor_overlay_candidate_validator_ozone.h",
     ]
 
     deps += [ "//ui/ozone" ]
   }
 }
 
+# These are part of the components_unittests build target.
 source_set("unit_tests") {
   testonly = true
   sources = [
     "buffer_queue_unittest.cc",
   ]
 
   if (!use_aura && !is_mac) {
     sources -= [ "buffer_queue_unittest.cc" ]
   }
 
@@ skipping 81 matching lines @@
     "//skia",
     "//testing/gmock",
     "//testing/gtest",
     "//ui/gl:test_support",
   ]
 
   data_deps = [
     "//third_party/mesa:osmesa",
   ]
 }