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/dbus/message.cc b/dbus/message.cc
index ce53a48..737b0c4 100644
--- a/dbus/message.cc
+++ b/dbus/message.cc
@@ -87,7 +87,7 @@ std::string Message::GetMessageTypeAsString() {
       return "MESSAGE_ERROR";
   }
   NOTREACHED();
-  return "";
+  return std::string();
 }
 
 std::string Message::ToStringInternal(const std::string& indent,
@@ -251,7 +251,7 @@ std::string Message::ToStringInternal(const std::string& indent,
 // ...
 std::string Message::ToString() {
   if (!raw_message_)
-    return "";
+    return std::string();
 
   // Generate headers first.
   std::string headers;
@@ -268,7 +268,7 @@ std::string Message::ToString() {
 
   // Generate the payload.
   MessageReader reader(this);
-  return headers + "\n" + ToStringInternal("", &reader);
+  return headers + "\n" + ToStringInternal(std::string(), &reader);
 }
 
 bool Message::SetDestination(const std::string& destination) {