Removed unnecessary returning by reference to simplify code.

BUG=137129

Review URL: https://chromiumcodereview.appspot.com/10958052

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@158200 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 72 insertions, 66 deletions

diff --git a/chrome/service/cloud_print/cloud_print_proxy.cc b/chrome/service/cloud_print/cloud_print_proxy.cc
index 416eddb1..b6eff89 100644
--- a/chrome/service/cloud_print/cloud_print_proxy.cc
+++ b/chrome/service/cloud_print/cloud_print_proxy.cc
@@ -90,13 +90,11 @@ void CloudPrintProxy::EnableForUser(const std::string& lsid) {
   DCHECK(backend_.get());
   // Read persisted robot credentials because we may decide to reuse it if the
   // passed in LSID belongs the same user.
-  std::string robot_refresh_token;
-  service_prefs_->GetString(prefs::kCloudPrintRobotRefreshToken,
-                            &robot_refresh_token);
-  std::string robot_email;
-  service_prefs_->GetString(prefs::kCloudPrintRobotEmail,
-                            &robot_email);
-  service_prefs_->GetString(prefs::kCloudPrintEmail, &user_email_);
+  std::string robot_refresh_token =
+      service_prefs_->GetString(prefs::kCloudPrintRobotRefreshToken, "");
+  std::string robot_email =
+      service_prefs_->GetString(prefs::kCloudPrintRobotEmail, "");
+  user_email_ = service_prefs_->GetString(prefs::kCloudPrintEmail, user_email_);
 
   // If we have been passed in an LSID, we want to use this to authenticate.
   // Else we will try and retrieve the last used auth tokens from prefs.
@@ -110,9 +108,8 @@ void CloudPrintProxy::EnableForUser(const std::string& lsid) {
       backend_->InitializeWithRobotToken(robot_refresh_token, robot_email);
     } else {
       // Finally see if we have persisted user credentials (legacy case).
-      std::string cloud_print_token;
-      service_prefs_->GetString(prefs::kCloudPrintAuthToken,
-                                &cloud_print_token);
+      std::string cloud_print_token =
+          service_prefs_->GetString(prefs::kCloudPrintAuthToken, "");
       DCHECK(!cloud_print_token.empty());
       backend_->InitializeWithToken(cloud_print_token);
     }
@@ -146,8 +143,8 @@ bool CloudPrintProxy::CreateBackend() {
 
   // By default we don't poll for jobs when we lose XMPP connection. But this
   // behavior can be overridden by a preference.
-  bool enable_job_poll = false;
-  service_prefs_->GetBoolean(prefs::kCloudPrintEnableJobPoll, &enable_job_poll);
+  bool enable_job_poll =
+    service_prefs_->GetBoolean(prefs::kCloudPrintEnableJobPoll, false);
 
   gaia::OAuthClientInfo oauth_client_info;
   oauth_client_info.client_id =
@@ -156,7 +153,6 @@ bool CloudPrintProxy::CreateBackend() {
     google_apis::GetOAuth2ClientSecret(google_apis::CLIENT_CLOUD_PRINT);
   backend_.reset(new CloudPrintProxyBackend(this, settings_, oauth_client_info,
                                             enable_job_poll));
-
   return true;
 }
 
@@ -191,7 +187,7 @@ void CloudPrintProxy::GetProxyInfo(cloud_print::CloudPrintProxyInfo* info) {
   // If the Cloud Print service is not enabled, we may need to read the old
   // value of proxy_id from prefs.
   if (info->proxy_id.empty())
-    service_prefs_->GetString(prefs::kCloudPrintProxyId, &info->proxy_id);
+    info->proxy_id = service_prefs_->GetString(prefs::kCloudPrintProxyId, "");
 }
 
 void CloudPrintProxy::CheckCloudPrintProxyPolicy() {
diff --git a/chrome/service/cloud_print/connector_settings.cc b/chrome/service/cloud_print/connector_settings.cc
index 667dd5b..f400914 100644
--- a/chrome/service/cloud_print/connector_settings.cc
+++ b/chrome/service/cloud_print/connector_settings.cc
@@ -17,7 +17,8 @@ const char kDeleteOnEnumFail[] = "delete_on_enum_fail";
 
 }  // namespace
 
-ConnectorSettings::ConnectorSettings() : delete_on_enum_fail_(false) {
+ConnectorSettings::ConnectorSettings()
+  : delete_on_enum_fail_(false) {
 }
 
 ConnectorSettings::~ConnectorSettings() {
@@ -26,7 +27,7 @@ ConnectorSettings::~ConnectorSettings() {
 void ConnectorSettings::InitFrom(ServiceProcessPrefs* prefs) {
   CopyFrom(ConnectorSettings());
 
-  prefs->GetString(prefs::kCloudPrintProxyId, &proxy_id_);
+  proxy_id_ = prefs->GetString(prefs::kCloudPrintProxyId, "");
   if (proxy_id_.empty()) {
     proxy_id_ = cloud_print::PrintSystem::GenerateProxyId();
     prefs->SetString(prefs::kCloudPrintProxyId, proxy_id_);
@@ -34,24 +35,22 @@ void ConnectorSettings::InitFrom(ServiceProcessPrefs* prefs) {
   }
 
   // Getting print system specific settings from the preferences.
-  const base::DictionaryValue* print_system_settings = NULL;
-  prefs->GetDictionary(prefs::kCloudPrintPrintSystemSettings,
-                       &print_system_settings);
+  const base::DictionaryValue* print_system_settings =
+      prefs->GetDictionary(prefs::kCloudPrintPrintSystemSettings);
   if (print_system_settings) {
     print_system_settings_.reset(print_system_settings->DeepCopy());
-    // TODO(vitalybuka) : Consider to move option from print_system_settings.
+    // TODO(vitalybuka) : Consider to rename and move out option from
+    // print_system_settings.
     print_system_settings_->GetBoolean(kDeleteOnEnumFail,
                                        &delete_on_enum_fail_);
   }
 
   // Check if there is an override for the cloud print server URL.
-  std::string cloud_print_server_url_str;
-  prefs->GetString(prefs::kCloudPrintServiceURL,
-                   &cloud_print_server_url_str);
-  if (cloud_print_server_url_str.empty()) {
-    cloud_print_server_url_str = kDefaultCloudPrintServerUrl;
+  server_url_ = GURL(prefs->GetString(prefs::kCloudPrintServiceURL, ""));
+  DCHECK(server_url_.is_empty() || server_url_.is_valid());
+  if (server_url_.is_empty() || !server_url_.is_valid()) {
+    server_url_ = GURL(kDefaultCloudPrintServerUrl);
   }
-  server_url_ = GURL(cloud_print_server_url_str.c_str());
   DCHECK(server_url_.is_valid());
 }
 
diff --git a/chrome/service/service_process.cc b/chrome/service/service_process.cc
index d585f30..21d8334 100644
--- a/chrome/service/service_process.cc
+++ b/chrome/service/service_process.cc
@@ -175,7 +175,7 @@ bool ServiceProcess::Initialize(MessageLoopForUI* message_loop,
   } else {
     // If no command-line value was specified, read the last used locale from
     // the prefs.
-    service_prefs_->GetString(prefs::kApplicationLocale, &locale);
+    locale = service_prefs_->GetString(prefs::kApplicationLocale, "");
     // If no locale was specified anywhere, use the default one.
     if (locale.empty())
       locale = kDefaultServiceProcessLocale;
@@ -185,23 +185,13 @@ bool ServiceProcess::Initialize(MessageLoopForUI* message_loop,
   PrepareRestartOnCrashEnviroment(command_line);
 
   // Enable Cloud Print if needed. First check the command-line.
-  bool cloud_print_proxy_enabled =
-      command_line.HasSwitch(switches::kEnableCloudPrintProxy);
-  if (!cloud_print_proxy_enabled) {
-    // Then check if the cloud print proxy was previously enabled.
-    service_prefs_->GetBoolean(prefs::kCloudPrintProxyEnabled,
-                               &cloud_print_proxy_enabled);
-  }
-
-  if (cloud_print_proxy_enabled) {
+  // Then check if the cloud print proxy was previously enabled.
+  if (command_line.HasSwitch(switches::kEnableCloudPrintProxy) ||
+      service_prefs_->GetBoolean(prefs::kCloudPrintProxyEnabled, false)) {
     GetCloudPrintProxy()->EnableForUser(lsid);
   }
   // Enable Virtual Printer Driver if needed.
-  bool virtual_printer_driver_enabled = false;
-  service_prefs_->GetBoolean(prefs::kVirtualPrinterDriverEnabled,
-                             &virtual_printer_driver_enabled);
-
-  if (virtual_printer_driver_enabled) {
+  if (service_prefs_->GetBoolean(prefs::kVirtualPrinterDriverEnabled, false)) {
     // Register the fact that there is at least one
     // service needing the process.
     OnServiceEnabled();
diff --git a/chrome/service/service_process_prefs.cc b/chrome/service/service_process_prefs.cc
index b925e2b..e1aca1a1 100644
--- a/chrome/service/service_process_prefs.cc
+++ b/chrome/service/service_process_prefs.cc
@@ -22,11 +22,16 @@ void ServiceProcessPrefs::WritePrefs() {
   prefs_->CommitPendingWrite();
 }
 
-void ServiceProcessPrefs::GetString(const std::string& key,
-                                    std::string* result) const {
+std::string ServiceProcessPrefs::GetString(
+    const std::string& key,
+    const std::string& default_value) const {
   const Value* value;
-  if (prefs_->GetValue(key, &value) == PersistentPrefStore::READ_OK)
-    value->GetAsString(result);
+  std::string result;
+  if (prefs_->GetValue(key, &value) != PersistentPrefStore::READ_OK ||
+      !value->GetAsString(&result)) {
+    return default_value;
+  }
+  return result;
 }
 
 void ServiceProcessPrefs::SetString(const std::string& key,
@@ -34,28 +39,44 @@ void ServiceProcessPrefs::SetString(const std::string& key,
   prefs_->SetValue(key, Value::CreateStringValue(value));
 }
 
-void ServiceProcessPrefs::GetBoolean(const std::string& key,
-                                     bool* result) const {
+bool ServiceProcessPrefs::GetBoolean(const std::string& key,
+                                     bool default_value) const {
   const Value* value;
-  if (prefs_->GetValue(key, &value) == PersistentPrefStore::READ_OK)
-    value->GetAsBoolean(result);
+  bool result = false;
+  if (prefs_->GetValue(key, &value) != PersistentPrefStore::READ_OK ||
+      !value->GetAsBoolean(&result)) {
+    return default_value;
+  }
+  return result;
 }
 
 void ServiceProcessPrefs::SetBoolean(const std::string& key, bool value) {
   prefs_->SetValue(key, Value::CreateBooleanValue(value));
 }
 
-void ServiceProcessPrefs::GetDictionary(const std::string& key,
-                                        const DictionaryValue** result) const {
+const DictionaryValue* ServiceProcessPrefs::GetDictionary(
+    const std::string& key) const {
   const Value* value;
   if (prefs_->GetValue(key, &value) != PersistentPrefStore::READ_OK ||
       !value->IsType(Value::TYPE_DICTIONARY)) {
-    return;
+    return NULL;
   }
 
-  *result = static_cast<const DictionaryValue*>(value);
+  return static_cast<const DictionaryValue*>(value);
+}
+
+const base::ListValue* ServiceProcessPrefs::GetList(
+    const std::string& key) const {
+  const Value* value;
+  if (prefs_->GetValue(key, &value) != PersistentPrefStore::READ_OK ||
+    !value->IsType(Value::TYPE_LIST)) {
+      return NULL;
+  }
+
+  return static_cast<const ListValue*>(value);
 }
 
 void ServiceProcessPrefs::RemovePref(const std::string& key) {
   prefs_->RemoveValue(key);
 }
+
diff --git a/chrome/service/service_process_prefs.h b/chrome/service/service_process_prefs.h
index 74a674d..d03fda9 100644
--- a/chrome/service/service_process_prefs.h
+++ b/chrome/service/service_process_prefs.h
@@ -11,6 +11,7 @@
 
 namespace base {
 class DictionaryValue;
+class ListValue;
 }
 
 // Manages persistent preferences for the service process. This is basically a
@@ -29,21 +30,24 @@ class ServiceProcessPrefs {
   // Write the data to the backing file.
   void WritePrefs();
 
-  // Get a string preference for |key| and store it in |result|.
-  void GetString(const std::string& key, std::string* result) const;
+  // Returns a string preference for |key|.
+  std::string GetString(const std::string& key,
+                        const std::string& default_value) const;
 
   // Set a string |value| for |key|.
   void SetString(const std::string& key, const std::string& value);
 
-  // Get a boolean preference for |key| and store it in |result|.
-  void GetBoolean(const std::string& key, bool* result) const;
+  // Returns a boolean preference for |key|.
+  bool GetBoolean(const std::string& key, bool default_value) const;
 
   // Set a boolean |value| for |key|.
   void SetBoolean(const std::string& key, bool value);
 
-  // Get a dictionary preference for |key| and store it in |result|.
-  void GetDictionary(const std::string& key,
-                     const base::DictionaryValue** result) const;
+  // Returns a dictionary preference for |key|.
+  const base::DictionaryValue* GetDictionary(const std::string& key) const;
+
+  // Returns a list for |key|.
+  const base::ListValue* GetList(const std::string& key) const;
 
   // Removes the pref specified by |key|.
   void RemovePref(const std::string& key);
diff --git a/chrome/service/service_process_prefs_unittest.cc b/chrome/service/service_process_prefs_unittest.cc
index 67ac5da..0268395 100644
--- a/chrome/service/service_process_prefs_unittest.cc
+++ b/chrome/service/service_process_prefs_unittest.cc
@@ -40,11 +40,7 @@ TEST_F(ServiceProcessPrefsTest, RetrievePrefs) {
   prefs_->SetBoolean("testb", false);   // overwrite
   prefs_->SetString("tests", "");   // overwrite
   prefs_->ReadPrefs();
-  bool testb;
-  prefs_->GetBoolean("testb", &testb);
-  EXPECT_EQ(testb, true);
-  std::string tests;
-  prefs_->GetString("tests", &tests);
-  EXPECT_EQ(tests, "testvalue");
+  EXPECT_EQ(prefs_->GetBoolean("testb", false), true);
+  EXPECT_EQ(prefs_->GetString("tests", ""), "testvalue");
 }