Move app_installer into chromium.

chrome/app_installer/app_installer.gypi

+# Copyright 2014 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.
+
+{
+  'conditions': [
+    ['OS=="win"', {
+      'targets': [
+        # TODO(jackhou): Add a version resource (using
+        # version_resource_rules.gypi).
+        {
+          'target_name': 'app_installer',
+          'type': 'executable',
+          'dependencies': [
+            'installer_util',
+            'installer_util_strings',
+            'launcher_support',
+            'common_constants.gyp:common_constants',
+            '../base/base.gyp:base',
+            '../third_party/omaha/omaha.gyp:omaha_extractor',
+          ],
+          'include_dirs': [
+            '..',
+            '<(INTERMEDIATE_DIR)',
+          ],
+          'sources': [
+            'win/app_installer_main.cc',
+          ],
+          'msvs_settings': {
+            'VCLinkerTool': {
+              'SubSystem': '2',     # Set /SUBSYSTEM:WINDOWS
+            },
+            'VCManifestTool': {
+              'AdditionalManifestFiles': [
+                'app_installer/win/app_installer.exe.manifest',
+              ],
+            },
+          },
+        },
+      ],
+    }],
+  ],
+}