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

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=193020

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

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@193040 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 2 insertions, 2 deletions

diff --git a/dbus/end_to_end_async_unittest.cc b/dbus/end_to_end_async_unittest.cc
index 0a3446e..6943494 100644
--- a/dbus/end_to_end_async_unittest.cc
+++ b/dbus/end_to_end_async_unittest.cc
@@ -185,7 +185,7 @@ class EndToEndAsyncTest : public testing::Test {
       ASSERT_TRUE(reader.PopString(&response_string));
       response_strings_.push_back(response_string);
     } else {
-      response_strings_.push_back("");
+      response_strings_.push_back(std::string());
     }
     message_loop_.Quit();
   };
@@ -205,7 +205,7 @@ class EndToEndAsyncTest : public testing::Test {
       ASSERT_NE("", error->GetErrorName());
       error_names_.push_back(error->GetErrorName());
     } else {
-      error_names_.push_back("");
+      error_names_.push_back(std::string());
     }
     message_loop_.Quit();
   }