Android: Make webview builds more convenient.

Allow the top level Android.mk to include GypAndroid.mk if the relevant
environment variable is set, to avoid having to edit this file to build
in the Android tree without breaking other Android builds. Also, provide
a gyp wrapper for webview which passes the correct options.

BUG=

Review URL: https://codereview.chromium.org/11090069

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@161566 0039d316-1c4b-4281-b951-d872f2087c98

Android.mk

@@ -2,5 +2,12 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-# This is an empty Android makefile to prevent the Android build system from
-# erroneously picking up other Android.mk files in the Chromium tree.
+# This Android makefile is used to build WebView in the Android build system.
+# gyp autogenerates the real makefiles, which we just include here if we are
+# doing a WebView build. For other builds, this makefile does nothing, which
+# prevents the Android build system from mistakenly loading any other
+# Android.mk that may exist in the Chromium tree.
+
+ifdef CHROME_ANDROID_BUILD_WEBVIEW
+include $(call my-dir)/GypAndroid.mk
+endif

android_webview/tools/gyp_webview

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# Copyright (c) 2012 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.
+
+# This script runs gyp with the configuration required to build WebView in the
+# Android build system. It is not necessary to source build/android/envsetup.sh
+# before running this script.
+
+set -e
+
+export CHROME_ANDROID_BUILD_WEBVIEW=1
+export CHROME_SRC="$(readlink -f "$(dirname "$0")/../..")"
+export PYTHONDONTWRITEBYTECODE=1
+. build/android/envsetup.sh
+android_gyp