Add GN build for parts of gpu and ozone.

ui/ozone/BUILD.gn

+# Copyright 2014 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("//ui/ozone/ozone.gni")
+
+platform_list_file = "$target_gen_dir/ozone_platform_list.cc"
+
+component("ozone") {
+  sources = [
+    platform_list_file,
+    # common/chromeos files are excluded automatically when building with
+    # chromeos=0, by exclusion rules in filename_rules.gypi due to the
+    # "chromeos" folder name.
+    "common/chromeos/native_display_delegate_ozone.cc",
+    "common/chromeos/native_display_delegate_ozone.h",
+    "ime/fake_input_method_context_ozone.cc",
+    "ime/fake_input_method_context_ozone.h",
+    "ime/input_method_context_factory_ozone.cc",
+    "ime/input_method_context_factory_ozone.h",
+    "ozone_platform.cc",
+    "ozone_platform.h",
+    "ozone_switches.cc",
+    "ozone_switches.h",
+  ]
+
+  defines = [ "OZONE_IMPLEMENTATION" ]
+
+  deps = [
+    ":generate_ozone_platform_list",
+    "//base",
+    "//skia",
+    "//ui/base:ui_base",
+    "//ui/events",
+    "//ui/gfx",
+    "//ui/gfx/geometry",
+    "//ui/gfx/ozone",
+  ]
+}
+
+# TODO(GYP) implement the ozone platforms. This should check the various
+# ozone_platform_*flags, and add deps and add to the ozone_platforms list for
+# the script below.
+ozone_platforms = ""
+
+action("generate_ozone_platform_list") {
+  script = "generate_ozone_platform_list.py"
+  outputs = [ platform_list_file ]
+
+  args = [
+    "--output_file=" + rebase_path(platform_list_file, root_build_dir),
+    "--default=$ozone_platform",
+    ozone_platforms,
+  ]
+}