Add a mimeHandler extension API.

extensions/extensions_resources.gyp

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'extensions_resources',
       'type': 'none',
       'variables': {
         'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/extensions',
       },
       'dependencies': [
+        'common/api/api.gyp:extensions_api_mojom',
         '../device/serial/serial.gyp:device_serial_mojo',
       ],
       'actions': [
         {
           'action_name': 'generate_extensions_resources',
           'variables': {
             'grit_grd_file': 'extensions_resources.grd',
           },
           'includes': [ '../build/grit_action.gypi' ],
         },
@@ skipping 12 matching lines @@
               '-E', 'mojom_root=<(SHARED_INTERMEDIATE_DIR)',
             ],
           },
           'includes': [ '../build/grit_action.gypi' ],
         },
       ],
       'includes': [ '../build/grit_target.gypi' ],
     }
   ]
 }