Remove HttpNetworkSession::enabled_protocols_.

* Remove HttpNetworkSession::enabled_protocols_.
* Spell out AlternateProtocol enum values in
  HttpNetworkSession::IsProtocolEnabled() and in
  HttpServerProperties::IsAlternateProtocolValid().
* Remove ALTERNATE_PROTOCOL_MAXIMUM_VALID_VERSION,
  ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION, enum AlternateProtocolSize.

BUG=116575

Review-Url: https://codereview.chromium.org/2362233002
Cr-Commit-Position: refs/heads/master@{#420731}

net/http/http_network_session.cc

@@ -208,25 +208,8 @@ HttpNetworkSession::HttpNetworkSession(const Params& params)
   websocket_socket_pool_manager_.reset(CreateSocketPoolManager(
       WEBSOCKET_SOCKET_POOL, params, ssl_session_cache_shard));
 
-  for (int i = ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION;
-       i <= ALTERNATE_PROTOCOL_MAXIMUM_VALID_VERSION; ++i) {
-    enabled_protocols_[i - ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION] = false;
-  }
-
-  // TODO(rtenneti): https://crbug.com/116575
-  // Consider combining the NextProto and AlternateProtocol.
   if (params_.enable_http2) {
     next_protos_.push_back(kProtoHTTP2);
-    AlternateProtocol alternate = AlternateProtocolFromNextProto(kProtoHTTP2);
-    enabled_protocols_[alternate - ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION] =
-        true;
-  }
-
-  if (params_.enable_quic) {
-    AlternateProtocol alternate =
-        AlternateProtocolFromNextProto(kProtoQUIC1SPDY3);
-    enabled_protocols_[alternate - ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION] =
-        true;
   }
 
   next_protos_.push_back(kProtoHTTP11);
@@ -356,9 +339,17 @@ void HttpNetworkSession::CloseIdleConnections() {
 }
 
 bool HttpNetworkSession::IsProtocolEnabled(AlternateProtocol protocol) const {
-  DCHECK(IsAlternateProtocolValid(protocol));
-  return enabled_protocols_[
-      protocol - ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION];
+  switch (protocol) {
+    case NPN_HTTP_2:
+      return params_.enable_http2;
+    case QUIC:
+      return params_.enable_quic;
+    case UNINITIALIZED_ALTERNATE_PROTOCOL:
+      NOTREACHED();
+      return false;
+  }
+  NOTREACHED();
+  return false;
 }
 
 void HttpNetworkSession::GetAlpnProtos(NextProtoVector* alpn_protos) const {

net/http/http_network_session.h

@@ -299,7 +299,6 @@ class NET_EXPORT HttpNetworkSession
   std::set<HttpResponseBodyDrainer*> response_drainers_;
 
   NextProtoVector next_protos_;
-  bool enabled_protocols_[NUM_VALID_ALTERNATE_PROTOCOLS];
 
   Params params_;
 

net/http/http_server_properties.cc

@@ -26,8 +26,16 @@ void HistogramBrokenAlternateProtocolLocation(
 }
 
 bool IsAlternateProtocolValid(AlternateProtocol protocol) {
-  return protocol >= ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION &&
-      protocol <= ALTERNATE_PROTOCOL_MAXIMUM_VALID_VERSION;
+  switch (protocol) {
+    case NPN_HTTP_2:
+      return true;
+    case QUIC:
+      return true;
+    case UNINITIALIZED_ALTERNATE_PROTOCOL:
+      return false;
+  }
+  NOTREACHED();
+  return false;
 }
 
 const char* AlternateProtocolToString(AlternateProtocol protocol) {

net/http/http_server_properties.h

@@ -67,23 +67,12 @@ NET_EXPORT void HistogramBrokenAlternateProtocolLocation(
 
 enum AlternateProtocol {
   NPN_HTTP_2,
-  ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION = NPN_HTTP_2,
   QUIC,
-  ALTERNATE_PROTOCOL_MAXIMUM_VALID_VERSION = QUIC,
   UNINITIALIZED_ALTERNATE_PROTOCOL,
 };
 
-// Simply returns whether |protocol| is between
-// ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION and
-// ALTERNATE_PROTOCOL_MAXIMUM_VALID_VERSION (inclusive).
 NET_EXPORT bool IsAlternateProtocolValid(AlternateProtocol protocol);
 
-enum AlternateProtocolSize {
-  NUM_VALID_ALTERNATE_PROTOCOLS =
-    ALTERNATE_PROTOCOL_MAXIMUM_VALID_VERSION -
-    ALTERNATE_PROTOCOL_MINIMUM_VALID_VERSION + 1,
-};
-
 NET_EXPORT const char* AlternateProtocolToString(AlternateProtocol protocol);
 NET_EXPORT AlternateProtocol AlternateProtocolFromString(
     const std::string& str);