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

tools/android/audio_focus_grabber/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/rules.gni")
 
-# GYP: //tools/android/audio_focus_grabber/audio_focus_grabber.gyp:audio_focus_grabber_apk
 android_apk("audio_focus_grabber_apk") {
   testonly = true
   android_manifest = "java/AndroidManifest.xml"
   apk_name = "AudioFocusGrabber"
 
   deps = [
     ":audio_focus_grabber_apk_resources",
     "//base:base_java",
     "//third_party/android_tools:android_support_v4_java",
   ]
 
   java_files = [
     "java/src/org/chromium/tools/audio_focus_grabber/AudioFocusGrabberActivity.java",
     "java/src/org/chromium/tools/audio_focus_grabber/AudioFocusGrabberListenerService.java",
   ]
 }
 
 android_resources("audio_focus_grabber_apk_resources") {
   testonly = true
   resource_dirs = [ "java/res" ]
   android_manifest = "java/AndroidManifest.xml"
 }