Use jinja2 to template webview manifest files.

android_webview/android_webview.gyp

 # Copyright 2009 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.
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
       'target_name': 'android_webview_pak',
@@ skipping 370 matching lines @@
             'R_package': 'org.chromium.android_webview',
             'R_package_relpath': 'org/chromium/android_webview',
           },
           'includes': [ '../build/java.gypi' ],
         },
         {
           'target_name': 'system_webview_apk',
           'variables': {
             'apk_name': 'SystemWebView',
             'android_sdk_jar': '../third_party/android_platform/webview/frameworks_5.1.0_r1.jar',
-            'android_manifest_path': 'apk/java/AndroidManifest.xml',
+            'android_manifest_template_path': 'apk/java/AndroidManifest.xml',

[Torne, 2015/03/30 14:02:38]

This will be the same for all the users of system_webview_apk_common as well, we
should put that in the gypi too.

[Tobias Sargeant, 2015/03/30 15:54:14]

Done.

+            'android_manifest_template_vars': [ ],
             'java_in_dir': 'glue/java',
             'resource_dir': 'apk/java/res',
           },
           'includes': [ 'apk/system_webview_apk_common.gypi' ],
         },
       ],
      }, {  # android_webview_build==1
       'targets': [
         {
           'target_name': 'android_webview_jarjar_ui_resources',
@@ skipping 35 matching lines @@
             'android_webview_jarjar_content_resources',
             'android_webview_jarjar_ui_resources',
             'android_webview_jarjar_web_contents_delegate_android_resources',
             'android_webview_strings_grd',
           ],
         },
       ],
     }],
   ],
 }