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

tools/android/forwarder/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/symlink.gni")
 
-# GYP: //tools/android/forwarder/forwarder.gyp:forwarder
 executable("forwarder") {
   sources = [
     "forwarder.cc",
   ]
   deps = [
     "//base",
     "//build/config/sanitizers:deps",
     "//tools/android/common",
   ]
 }