Introduce CryptAuthClient, a class capable of performing all CryptAuth APIs.

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': [
     {
       'target_name': 'proximity_auth',
       'type': 'static_library',
       'include_dirs': [
@@ skipping 46 matching lines @@
       },
       'includes': [ '../build/protoc.gypi' ]
     },
     {
       'target_name': 'cryptauth',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
+        'cryptauth_proto',
         '../base/base.gyp:base',
         '../google_apis/google_apis.gyp:google_apis',
         '../net/net.gyp:net',
       ],
       'sources': [
+        "proximity_auth/cryptauth/cryptauth_access_token_fetcher.h",
         "proximity_auth/cryptauth/cryptauth_api_call_flow.cc",
         "proximity_auth/cryptauth/cryptauth_api_call_flow.h",
+        "proximity_auth/cryptauth/cryptauth_client.cc",
+        "proximity_auth/cryptauth/cryptauth_client.h",
+      ],
+      'export_dependent_settings': [
+        'cryptauth_proto',
       ],
     },
   ],
 }