Implement new compositor and ContentViewCore reparenting for VR Shell.

chrome/browser/android/vr_shell/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/android/rules.gni")
 import("//chrome/common/features.gni")
 import("//testing/test.gni")
 
 assert(enable_vr_shell && android_java_ui)
 
 static_library("vr_shell") {
   sources = [
     "animation.cc",
     "animation.h",
     "easing.cc",
     "easing.h",
     "ui_elements.cc",
     "ui_elements.h",
+    "vr_compositor.cc",
+    "vr_compositor.h",
     "vr_gl_util.cc",
     "vr_gl_util.h",
     "vr_math.cc",
     "vr_math.h",
     "vr_shell.cc",
     "vr_shell.h",
     "vr_shell_renderer.cc",
     "vr_shell_renderer.h",
   ]
 
@@ skipping 24 matching lines @@
   ]
 
   deps = [
     ":vr_shell",
     "//base/test:run_all_unittests",
     "//base/test:test_support",
     "//testing/gtest",
     "//ui/gfx/geometry",
   ]
 }