Rewrite std::string("") to std::string(), Linux edition.

This patch was generated by running the empty_string clang tool
across the Chromium Linux compilation database. Implicitly or
explicitly constructing std::string() with a "" argument is
inefficient as the caller needs to emit extra instructions to
pass an argument, and the constructor needlessly copies a byte
into internal storage. Rewriting these instances to simply call
the default constructor appears to save ~14-18 kilobytes on an
optimized release build.

BUG=none

Review URL: https://codereview.chromium.org/13145003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@193020 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 10 insertions, 7 deletions

diff --git a/chrome/browser/sync/profile_sync_service_startup_unittest.cc b/chrome/browser/sync/profile_sync_service_startup_unittest.cc
index 1a00308..d85946e 100644
--- a/chrome/browser/sync/profile_sync_service_startup_unittest.cc
+++ b/chrome/browser/sync/profile_sync_service_startup_unittest.cc
@@ -189,9 +189,10 @@ TEST_F(ProfileSyncServiceStartupTest, StartFirstTime) {
   // Create some tokens in the token service; the service will startup when
   // it is notified that tokens are available.
   sync_->SetSetupInProgress(true);
-  sync_->signin()->StartSignIn("test_user", "", "", "");
-  TokenServiceFactory::GetForProfile(profile_.get())->IssueAuthTokenForTest(
-      GaiaConstants::kSyncService, "sync_token");
+  sync_->signin()
+      ->StartSignIn("test_user", std::string(), std::string(), std::string());
+  TokenServiceFactory::GetForProfile(profile_.get())
+      ->IssueAuthTokenForTest(GaiaConstants::kSyncService, "sync_token");
   TokenServiceFactory::GetForProfile(profile_.get())->IssueAuthTokenForTest(
       GaiaConstants::kGaiaOAuth2LoginRefreshToken, "oauth2_login_token");
   sync_->SetSetupInProgress(false);
@@ -235,7 +236,8 @@ TEST_F(ProfileSyncServiceStartupTest, StartNoCredentials) {
   EXPECT_CALL(observer_, OnStateChanged()).Times(AnyNumber());
 
   sync_->SetSetupInProgress(true);
-  sync_->signin()->StartSignIn("test_user", "", "", "");
+  sync_->signin()
+      ->StartSignIn("test_user", std::string(), std::string(), std::string());
   // NOTE: Unlike StartFirstTime, this test does not issue any auth tokens.
   token_service->LoadTokensFromDB();
   sync_->SetSetupInProgress(false);
@@ -269,9 +271,10 @@ TEST_F(ProfileSyncServiceStartupTest, StartInvalidCredentials) {
   EXPECT_CALL(*data_type_manager, Stop()).Times(1);
   EXPECT_CALL(observer_, OnStateChanged()).Times(AnyNumber());
   sync_->SetSetupInProgress(true);
-  sync_->signin()->StartSignIn("test_user", "", "", "");
-  token_service->IssueAuthTokenForTest(
-      GaiaConstants::kSyncService, "sync_token");
+  sync_->signin()
+      ->StartSignIn("test_user", std::string(), std::string(), std::string());
+  token_service->IssueAuthTokenForTest(GaiaConstants::kSyncService,
+                                       "sync_token");
   sync_->SetSetupInProgress(false);
   MessageLoop::current()->Run();