Mojo: Simplify typemap usage.

content/content_common_mojo_bindings.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': [
     {
       # GN version: //content/common:mojo_bindings
       'target_name': 'content_common_mojo_bindings_mojom',
       'type': 'none',
       'variables': {
-        'mojom_extra_generator_args': [
-          '--typemap', '<(DEPTH)/url/mojo/origin.typemap',
-          '--typemap', '<(DEPTH)/url/mojo/gurl.typemap',
-        ],
         'mojom_files': [
           # NOTE: Sources duplicated in //content/common/BUILD.gn:mojo_bindings.
           'common/application_setup.mojom',
           'common/background_sync_service.mojom',
           'common/image_downloader/image_downloader.mojom',
           'common/leveldb_wrapper.mojom',
           'common/presentation/presentation_service.mojom',
           'common/process_control.mojom',
           'common/render_frame_setup.mojom',
           'common/service_worker/embedded_worker_setup.mojom',
           'common/storage_partition_service.mojom',
           'common/vr_service.mojom',
 
           # NOTE: Sources duplicated in
           # //content/public/common/BUILD.gn:mojo_bindings.
           'public/common/background_sync.mojom',
           'public/common/service_worker_event_status.mojom',
         ],
+        'mojom_typemaps': [
+          '../url/mojo/gurl.typemap',
+          '../url/mojo/origin.typemap',
+        ],
       },
       'dependencies': [
         '../components/leveldb/leveldb.gyp:leveldb_bindings_mojom',
         '../mojo/mojo_public.gyp:mojo_cpp_bindings',
         '../services/shell/shell.gyp:shell_public',
         '../skia/skia.gyp:skia_mojo',
         '../third_party/WebKit/public/blink.gyp:mojo_bindings',
         '../ui/mojo/geometry/mojo_bindings.gyp:mojo_geometry_bindings',
       ],
       'includes': [ '../mojo/mojom_bindings_generator_explicit.gypi' ],
     },
     {
       'target_name': 'content_common_mojo_bindings',
       'type': 'static_library',
       'variables': {
         'enable_wexit_time_destructors': 1,
       },
       'dependencies': [
         '../url/url.gyp:url_mojom',
         'content_common_mojo_bindings_mojom',
       ],
       'export_dependent_settings': [
         '../url/url.gyp:url_mojom',
       ],
     },
   ]
 }