Revert of android: Introduce a ui::PlatformWindow implementation for android.

ui/platform_window/android/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")
-import("//testing/test.gni")
-
-assert(is_android)
-
-component("android") {
-  output_name = "android_window"
-  sources = [
-    "platform_window_android.cc",
-    "platform_window_android.h",
-  ]
-
-  defines = [ "ANDROID_WINDOW_IMPLEMENTATION" ]
-
-  deps = [
-    "//base",
-    "//skia",
-    "//ui/events:events_base",
-    "//ui/gfx",
-    "//ui/gfx/geometry",
-    ":jni_headers",
-    ":platform_window_java",
-  ]
-}
-
-generate_jni("jni_headers") {
-  sources = [
-    "java/src/org/chromium/ui/PlatformWindowAndroid.java",
-  ]
-  jni_package = "android_window"
-}
-
-android_library("platform_window_java") {
-  java_files = [ "java/src/org/chromium/ui/PlatformWindowAndroid.java" ]
-  deps = [
-    "//base:base_java",
-  ]
-}