Remove GYP annotations from chrome, ui, tools GN files.

chrome/test/android/cast_emulator/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("//build/config/android/config.gni")
 import("//build/config/android/rules.gni")
 
-# GYP: //clank/native/clank.gyp:cast_emulator
 android_library("cast_emulator") {
   chromium_code = true
 
   java_files = [
     "src/org/chromium/chrome/browser/media/TestMediaRouteProvider.java",
     "src/org/chromium/chrome/browser/media/TestMediaRouteProviderService.java",
     "src/org/chromium/chrome/browser/media/RoutePublisher.java",
     "src/org/chromium/chrome/browser/media/remote/DummyPlayer.java",
     "src/org/chromium/chrome/browser/media/remote/LocalSessionManager.java",
     "src/org/chromium/chrome/browser/media/remote/MediaItem.java",
     "src/org/chromium/chrome/browser/media/remote/RemotePlaybackRoutePublisher.java",
     "src/org/chromium/chrome/browser/media/remote/RemoteSessionManager.java",
     "src/org/chromium/chrome/browser/media/router/DummyRoutePublisher.java",
   ]
   deps = [
     "//base:base_java",
     "//third_party/android_tools:android_support_v7_appcompat_java",
     "//third_party/android_tools:android_support_v7_mediarouter_java",
     google_play_services_library,
   ]
 }