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, 3 insertions, 3 deletions

diff --git a/net/base/dns_util.cc b/net/base/dns_util.cc
index 816095b..b94eff8 100644
--- a/net/base/dns_util.cc
+++ b/net/base/dns_util.cc
@@ -62,16 +62,16 @@ std::string DNSDomainToString(const base::StringPiece& domain) {
   for (unsigned i = 0; i < domain.size() && domain[i]; i += domain[i] + 1) {
 #if CHAR_MIN < 0
     if (domain[i] < 0)
-      return "";
+      return std::string();
 #endif
     if (domain[i] > 63)
-      return "";
+      return std::string();
 
     if (i)
       ret += ".";
 
     if (static_cast<unsigned>(domain[i]) + i + 1 > domain.size())
-      return "";
+      return std::string();
 
     domain.substr(i + 1, domain[i]).AppendToString(&ret);
   }