[url_launcher_web] Move third_party under src. (#3080)

Author: ditman

packages/url_launcher/url_launcher_web/CHANGELOG.md

@@ -1,3 +1,7 @@
+# 0.1.4+2
+
+- Move `lib/third_party` to `lib/src/third_party`.
+
 # 0.1.4+1
 
 - Add a more correct attribution to `package:platform_detect` code.

packages/url_launcher/url_launcher_web/lib/third_party/platform_detect/LICENSE renamed to packages/url_launcher/url_launcher_web/lib/src/third_party/platform_detect/LICENSE

@@ -1,10 +1,15 @@
+// Copyright 2019 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 'dart:async';
 import 'dart:html' as html;
 
 import 'package:flutter_web_plugins/flutter_web_plugins.dart';
 import 'package:meta/meta.dart';
 import 'package:url_launcher_platform_interface/url_launcher_platform_interface.dart';
-import 'third_party/platform_detect/browser.dart';
+
+import 'src/third_party/platform_detect/browser.dart';
 
 const _safariTargetTopSchemes = {
   'mailto',

packages/url_launcher/url_launcher_web/lib/third_party/platform_detect/README.md renamed to packages/url_launcher/url_launcher_web/lib/src/third_party/platform_detect/README.md

@@ -4,7 +4,7 @@ homepage: https://github.com/flutter/plugins/tree/master/packages/url_launcher/u
 # 0.1.y+z is compatible with 1.0.0, if you land a breaking change bump
 # the version to 2.0.0.
 # See more details: https://github.com/flutter/flutter/wiki/Package-migration-to-1.0.0
-version: 0.1.4+1
+version: 0.1.4+2
 
 flutter:
   plugin: