Generate all extension schema namespaces as "api" and instead vary the generated bundle names.

extensions/common/api/schemas.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.
 
 {
   'sources': [
     '<@(schema_files)',
   ],
   'variables': {
     'chromium_code': 1,
@@ skipping 57 matching lines @@
       'web_request_internal.json',
     ],
     'conditions': [
       ['chromeos==1', {
         'schema_files': [
           '<@(chromeos_schema_files)',
         ],
       }]
     ],
     'cc_dir': 'extensions/common/api',
-    'root_namespace': 'extensions::core_api::%(namespace)s',
+    'root_namespace': 'extensions::api::%(namespace)s',
+    'bundle_name': '',
     'impl_dir_': 'extensions/browser/api',
   },
 }