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/net/udp/udp_socket_unittest.cc b/net/udp/udp_socket_unittest.cc
index c2085ad..09a2806 100644
--- a/net/udp/udp_socket_unittest.cc
+++ b/net/udp/udp_socket_unittest.cc
@@ -38,7 +38,7 @@ class UDPSocketTest : public PlatformTest {
     if (rv == ERR_IO_PENDING)
       rv = callback.WaitForResult();
     if (rv < 0)
-      return "";  // error!
+      return std::string();  // error!
     return std::string(buffer_->data(), rv);
   }
 
@@ -82,7 +82,7 @@ class UDPSocketTest : public PlatformTest {
     if (rv == ERR_IO_PENDING)
       rv = callback.WaitForResult();
     if (rv < 0)
-      return "";  // error!
+      return std::string();  // error!
     return std::string(buffer_->data(), rv);
   }