[PresentationAPI] Implementing start/joinSession from WebPresentationClient to PresentationService.

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_files': [
           # NOTE: Sources duplicated in //content/common/BUILD.gn:mojo_bindings.
           'common/application_setup.mojom',
           'common/geolocation_service.mojom',
           'common/permission_service.mojom',
           'common/presentation/presentation_service.mojom',
+          'common/presentation/presentation_session.mojom',
           'common/render_frame_setup.mojom',
 
           # NOTE: Sources duplicated in
           # //content/public/common/BUILD.gn:mojo_bindings.
           'public/common/mojo_geoposition.mojom',
           'public/common/permission_status.mojom',
         ],
       },
       'includes': [ '../third_party/mojo/mojom_bindings_generator_explicit.gypi' ],
     },
     {
       'target_name': 'content_common_mojo_bindings',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
       'dependencies': [
         'content_common_mojo_bindings_mojom',
         '../mojo/mojo_base.gyp:mojo_environment_chromium',
         '../third_party/mojo/mojo_public.gyp:mojo_application_bindings',
         '../third_party/mojo/mojo_public.gyp:mojo_cpp_bindings',
       ]
     },
   ]
 }