arc: enable Android tracing from chrome://tracing in dev mode

components/arc/BUILD.gn

 # Copyright 2015 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("//mojo/public/tools/bindings/mojom.gni")
 import("//testing/test.gni")
 
 static_library("arc") {
   sources = [
     "arc_service_manager.cc",
@@ skipping 136 matching lines @@
     "common/net.mojom",
     "common/notifications.mojom",
     "common/obb_mounter.mojom",
     "common/policy.mojom",
     "common/power.mojom",
     "common/print.mojom",
     "common/process.mojom",
     "common/scale_factor.mojom",
     "common/screen_rect.mojom",
     "common/storage_manager.mojom",
+    "common/tracing.mojom",
     "common/tts.mojom",
     "common/video.mojom",
     "common/video_accelerator.mojom",
     "common/wallpaper.mojom",
   ]
 
   public_deps = [
     "//mojo/common:common_custom_types",
     "//ui/gfx/geometry/mojo",
   ]
@@ skipping 58 matching lines @@
     "//testing/gtest",
     "//ui/aura",
     "//ui/aura:test_support",
     "//ui/base:test_support",
     "//ui/base/ime",
     "//ui/events",
     "//ui/events:dom_keycode_converter",
     "//url:url",
   ]
 }