Persist the alternate protocol as a string not an int to allow the enum to be changed without affec…

net/http/http_server_properties.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/http/http_server_properties.h"
 
 #include "base/logging.h"
 #include "base/stringprintf.h"
 
 namespace net {
 
 const char kAlternateProtocolHeader[] = "Alternate-Protocol";
 const char* const kAlternateProtocolStrings[] = {
   "npn-spdy/1",
   "npn-spdy/2",
   "npn-spdy/3",
 };
+const char kBrokenAlternateProtocol[] = "Broken";
 
-static const char* AlternateProtocolToString(AlternateProtocol protocol) {
+const char* AlternateProtocolToString(AlternateProtocol protocol) {
   switch (protocol) {
     case NPN_SPDY_1:
     case NPN_SPDY_2:
     case NPN_SPDY_3:
       return kAlternateProtocolStrings[protocol];
     case ALTERNATE_PROTOCOL_BROKEN:
-      return "Broken";
+      return kBrokenAlternateProtocol;
     case UNINITIALIZED_ALTERNATE_PROTOCOL:
       return "Uninitialized";
     default:
       NOTREACHED();
       return "";
   }
 }
 
+AlternateProtocol AlternateProtocolFromString(const std::string& protocol) {
+  for (int i = NPN_SPDY_1; i < NUM_ALTERNATE_PROTOCOLS; ++i)
+    if (protocol == kAlternateProtocolStrings[i])
+      return static_cast<AlternateProtocol>(i);
+  if (protocol == kBrokenAlternateProtocol)
+    return ALTERNATE_PROTOCOL_BROKEN;
+  return UNINITIALIZED_ALTERNATE_PROTOCOL;
+}
+
+
 std::string PortAlternateProtocolPair::ToString() const {
   return base::StringPrintf("%d:%s", port,
                             AlternateProtocolToString(protocol));
 }
 
 }  // namespace net