Refactor ProximityAuthUIDelegate functions to ProximityAuthClient.

components/proximity_auth.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.
 
 {
   'targets': [
     {
       # GN version: //components/proximity_auth and
       # //components/proximity_auth/ble.
       'target_name': 'proximity_auth',
@@ skipping 85 matching lines @@
     },
     {
       'target_name': 'proximity_auth_test_support',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
         ':cryptauth_test_support',
         '../base/base.gyp:base',
+        '../testing/gmock.gyp:gmock',
       ],
       'sources': [
         "proximity_auth/device_to_device_responder_operations.cc",
         "proximity_auth/device_to_device_responder_operations.h",
+        "proximity_auth/mock_proximity_auth_client.cc",
+        "proximity_auth/mock_proximity_auth_client.h",
       ],
     },
     {
       # GN version: //components/proximity_auth/logging
       'target_name': 'proximity_auth_logging',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
@@ skipping 120 matching lines @@
         'proximity_auth/webui/proximity_auth_webui_handler.cc',
         'proximity_auth/webui/proximity_auth_webui_handler.h',
         'proximity_auth/webui/reachable_phone_flow.cc',
         'proximity_auth/webui/reachable_phone_flow.h',
         'proximity_auth/webui/url_constants.cc',
         'proximity_auth/webui/url_constants.h',
       ],
     },
   ],
 }