Optimize chained string concatenation in SPDY code.

net/spdy/spdy_framer.cc

Index: net/spdy/spdy_framer.cc
diff --git a/net/spdy/spdy_framer.cc b/net/spdy/spdy_framer.cc
index a02cb2e30ece9b31838a60eced37929a2a33592d..d8023491882df2d5150b347ea163cd2b8b9083f5 100644
--- a/net/spdy/spdy_framer.cc
+++ b/net/spdy/spdy_framer.cc
@@ -1339,15 +1339,11 @@ void SpdyFramer::WriteHeaderBlockToZ(const SpdyHeaderBlock* headers,
         // is currently last (and so doesn't have a trailing semicolon) won't
         // match if it's later in a non-final position. The same is true of
         // the first cookie.
-        if (i == 0 && cookie_values.size() == 1) {
-          cookie = cookie_values[i].as_string();
-        } else if (i == 0) {
-          cookie = cookie_values[i].as_string() + ";";
-        } else if (i < cookie_values.size() - 1) {
-          cookie = " " + cookie_values[i].as_string() + ";";
-        } else {
-          cookie = " " + cookie_values[i].as_string();
-        }
+        if (i > 0)
+          cookie.append(" ");
+        cookie.append(cookie_values[i].as_string());
+        if (i < cookie_values.size() - 1)
+          cookie.append(";");

[mmenke, 2015/03/09 20:21:58]

Isn't this the same as:

if (i > 0)
  cookie.append("; ");
cookie.append(cookie_values[i].as_string());

         WriteZ(cookie, kZCookieData, z);
       }
     } else if (it->first == "accept" ||