Introduce new SPDY Version UMA histogram.

net/spdy/spdy_session.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/spdy/spdy_session.h"
 
 #include <algorithm>
 #include <map>
 
 #include "base/basictypes.h"
@@ skipping 701 matching lines @@
     flow_control_state_ = FLOW_CONTROL_STREAM;
   } else {
     flow_control_state_ = FLOW_CONTROL_NONE;
   }
 
   buffered_spdy_framer_.reset(
       new BufferedSpdyFramer(NextProtoToSpdyMajorVersion(protocol_),
                              enable_compression_));
   buffered_spdy_framer_->set_visitor(this);
   buffered_spdy_framer_->set_debug_visitor(this);
-  UMA_HISTOGRAM_ENUMERATION("Net.SpdyVersion", protocol_, kProtoMaximumVersion);
+  UMA_HISTOGRAM_ENUMERATION(
+      "Net.SpdyVersion2",
+      protocol_ - kProtoSPDYMinimumVersion,
+      kProtoSPDYMaximumVersion - kProtoSPDYMinimumVersion + 1);
 #if defined(SPDY_PROXY_AUTH_ORIGIN)
   UMA_HISTOGRAM_BOOLEAN("Net.SpdySessions_DataReductionProxy",
                         host_port_pair().Equals(HostPortPair::FromURL(
                             GURL(SPDY_PROXY_AUTH_ORIGIN))));
 #endif
 
   net_log_.AddEvent(
       NetLog::TYPE_SPDY_SESSION_INITIALIZED,
       connection_->socket()->NetLog().source().ToEventParametersCallback());
 
@@ skipping 2498 matching lines @@
     if (!queue->empty()) {
       SpdyStreamId stream_id = queue->front();
       queue->pop_front();
       return stream_id;
     }
   }
   return 0;
 }
 
 }  // namespace net