Refactor CryptAuth component to be more testable.

components/proximity_auth/cryptauth/cryptauth_client_factory.cc

 // Copyright 2015 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.
 
 #include "components/proximity_auth/cryptauth/cryptauth_client_factory.h"
 
-#include "components/proximity_auth/cryptauth/cryptauth_account_token_fetcher.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "components/proximity_auth/cryptauth/cryptauth_access_token_fetcher.h"
+#include "components/proximity_auth/cryptauth/cryptauth_api_call_flow.h"
+#include "components/proximity_auth/cryptauth/cryptauth_client_impl.h"
+#include "google_apis/gaia/oauth2_token_service.h"
+#include "net/url_request/url_request_context_getter.h"
 
 namespace proximity_auth {
 
-CryptAuthClientFactory::CryptAuthClientFactory(
+namespace {
+
+class CryptAuthClientFactoryImpl : public CryptAuthClientFactory {
+ public:
+  CryptAuthClientFactoryImpl(
+      OAuth2TokenService* token_service,
+      const std::string& account_id,
+      scoped_refptr<net::URLRequestContextGetter> url_request_context,
+      const cryptauth::DeviceClassifier& device_classifier);
+  ~CryptAuthClientFactoryImpl() override;
+
+  // Creates and returns a CryptAuthClient instance that is owned by the caller.
+  scoped_ptr<CryptAuthClient> CreateInstance() override;
+
+ private:
+  OAuth2TokenService* token_service_;
+  const std::string account_id_;
+  const scoped_refptr<net::URLRequestContextGetter> url_request_context_;
+  const cryptauth::DeviceClassifier device_classifier_;
+
+  DISALLOW_COPY_AND_ASSIGN(CryptAuthClientFactoryImpl);
+};
+
+CryptAuthClientFactoryImpl::CryptAuthClientFactoryImpl(
     OAuth2TokenService* token_service,
     const std::string& account_id,
     scoped_refptr<net::URLRequestContextGetter> url_request_context,
     const cryptauth::DeviceClassifier& device_classifier)
     : token_service_(token_service),
       account_id_(account_id),
       url_request_context_(url_request_context),
       device_classifier_(device_classifier) {
 }
 
-CryptAuthClientFactory::~CryptAuthClientFactory() {
+CryptAuthClientFactoryImpl::~CryptAuthClientFactoryImpl() {
 }
 
-scoped_ptr<CryptAuthClient> CryptAuthClientFactory::CreateInstance() {
+scoped_ptr<CryptAuthClient> CryptAuthClientFactoryImpl::CreateInstance() {
   scoped_ptr<CryptAuthAccessTokenFetcher> access_token_fetcher(
-      new CryptAuthAccountTokenFetcher(token_service_, account_id_));
-  return make_scoped_ptr(new CryptAuthClient(
-      access_token_fetcher.Pass(), url_request_context_, device_classifier_));
+      CryptAuthAccessTokenFetcher::CreateDefault(token_service_, account_id_));
+  return make_scoped_ptr(new CryptAuthClientImpl(
+      make_scoped_ptr(new CryptAuthApiCallFlow()), access_token_fetcher.Pass(),
+      url_request_context_, device_classifier_));
+}
+
+}  // namespace
+
+// static.
+scoped_ptr<CryptAuthClientFactory> CryptAuthClientFactory::CreateDefault(
+    OAuth2TokenService* token_service,
+    const std::string& account_id,
+    scoped_refptr<net::URLRequestContextGetter> url_request_context,
+    const cryptauth::DeviceClassifier& device_classifier) {
+  return make_scoped_ptr(new CryptAuthClientFactoryImpl(
+      token_service, account_id, url_request_context, device_classifier));
 }
 
 }  // namespace proximity_auth