Fix some unintentional pointer arithmetic.

net/spdy/spdy_session.cc

Index: net/spdy/spdy_session.cc
diff --git a/net/spdy/spdy_session.cc b/net/spdy/spdy_session.cc
index c16de270b007eac0c1ef12a9373f3df6b0c27cee..a65eec89e64f325e2ae13632e8b684684215da3c 100644
--- a/net/spdy/spdy_session.cc
+++ b/net/spdy/spdy_session.cc
@@ -1329,8 +1329,9 @@ void SpdySession::OnSyn(const spdy::SpdySynStreamControlFrame& frame,
     LOG(WARNING) << "Received OnSyn with inactive associated stream "
                << associated_stream_id;
     ResetStream(stream_id, spdy::INVALID_ASSOCIATED_STREAM,
-                "Received OnSyn with inactive associated stream " +
-                associated_stream_id);
+                base::StringPrintf(
+                    "Received OnSyn with inactive associated stream %d",
+                    associated_stream_id));
     return;
   }
 
@@ -1341,7 +1342,9 @@ void SpdySession::OnSyn(const spdy::SpdySynStreamControlFrame& frame,
     LOG(WARNING) << "Rejected Cross Origin Push Stream "
                  << associated_stream_id;
     ResetStream(stream_id, spdy::REFUSED_STREAM,
-                "Rejected Cross Origin Push Stream " + associated_stream_id);
+                base::StringPrintf(
+                    "Rejected Cross Origin Push Stream %d",
+                    associated_stream_id));
     return;
   }
 
@@ -1609,8 +1612,9 @@ void SpdySession::OnWindowUpdate(
     LOG(WARNING) << "Received WINDOW_UPDATE with an invalid delta_window_size "
                  << delta_window_size;
     ResetStream(stream_id, spdy::FLOW_CONTROL_ERROR,
-                "Received WINDOW_UPDATE with an invalid delta_window_size "
-                + delta_window_size);
+                base::StringPrintf(
+                    "Received WINDOW_UPDATE with an invalid "
+                    "delta_window_size %d", delta_window_size));
     return;
   }