Massively simplify the NetworkChangeNotifier infrastructure:

  * Use a process-wide object (singleton pattern)
  * Create/destroy this object on the main thread, make it outlive all consumers
  * Make observer-related functions threadsafe

As a result, the notifier can now be used by any thread (eliminating things like NetworkChangeObserverProxy and NetworkChangeNotifierProxy, and expanding its usefulness); its creation and inner workings are much simplified (eliminating implementation-specific classes); and it is simpler to access (eliminating things like NetworkChangeNotifierThread and a LOT of passing pointers around).

BUG=none
TEST=Unittests; network changes still trigger notifications
Review URL: http://codereview.chromium.org/2802015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@50895 0039d316-1c4b-4281-b951-d872f2087c98

8 files changed, 46 insertions, 83 deletions

diff --git a/net/http/http_cache.cc b/net/http/http_cache.cc
index ef9198c..7e73d94 100644
--- a/net/http/http_cache.cc
+++ b/net/http/http_cache.cc
@@ -222,8 +222,7 @@ void HttpCache::MetadataWriter::OnIOComplete(int result) {
 
 //-----------------------------------------------------------------------------
 
-HttpCache::HttpCache(NetworkChangeNotifier* network_change_notifier,
-                     HostResolver* host_resolver, ProxyService* proxy_service,
+HttpCache::HttpCache(HostResolver* host_resolver, ProxyService* proxy_service,
                      SSLConfigService* ssl_config_service,
                      HttpAuthHandlerFactory* http_auth_handler_factory,
                      HttpNetworkDelegate* network_delegate,
@@ -233,11 +232,9 @@ HttpCache::HttpCache(NetworkChangeNotifier* network_change_notifier,
       temp_backend_(NULL),
       building_backend_(false),
       mode_(NORMAL),
-      network_layer_(HttpNetworkLayer::CreateFactory(
-          network_change_notifier, host_resolver, proxy_service,
-          ssl_config_service, http_auth_handler_factory,
-          network_delegate,
-          net_log)),
+      network_layer_(HttpNetworkLayer::CreateFactory(host_resolver,
+          proxy_service, ssl_config_service, http_auth_handler_factory,
+          network_delegate, net_log)),
       ALLOW_THIS_IN_INITIALIZER_LIST(task_factory_(this)),
       enable_range_support_(true) {
 }
diff --git a/net/http/http_cache.h b/net/http/http_cache.h
index 9ed20b4..734e58d 100644
--- a/net/http/http_cache.h
+++ b/net/http/http_cache.h
@@ -46,7 +46,6 @@ struct HttpRequestInfo;
 class HttpResponseInfo;
 class IOBuffer;
 class NetLog;
-class NetworkChangeNotifier;
 class ProxyService;
 class SSLConfigService;
 class ViewCacheHelper;
@@ -113,8 +112,8 @@ class HttpCache : public HttpTransactionFactory,
 
   // The disk cache is initialized lazily (by CreateTransaction) in this case.
   // The  HttpCache takes ownership of the |backend_factory|.
-  HttpCache(NetworkChangeNotifier* network_change_notifier,
-            HostResolver* host_resolver, ProxyService* proxy_service,
+  HttpCache(HostResolver* host_resolver,
+            ProxyService* proxy_service,
             SSLConfigService* ssl_config_service,
             HttpAuthHandlerFactory* http_auth_handler_factory,
             HttpNetworkDelegate* network_delegate,
diff --git a/net/http/http_network_layer.cc b/net/http/http_network_layer.cc
index 2329627..27c6272 100644
--- a/net/http/http_network_layer.cc
+++ b/net/http/http_network_layer.cc
@@ -21,7 +21,6 @@ namespace net {
 
 // static
 HttpTransactionFactory* HttpNetworkLayer::CreateFactory(
-    NetworkChangeNotifier* network_change_notifier,
     HostResolver* host_resolver,
     ProxyService* proxy_service,
     SSLConfigService* ssl_config_service,
@@ -31,7 +30,6 @@ HttpTransactionFactory* HttpNetworkLayer::CreateFactory(
   DCHECK(proxy_service);
 
   return new HttpNetworkLayer(ClientSocketFactory::GetDefaultFactory(),
-                              network_change_notifier,
                               host_resolver, proxy_service, ssl_config_service,
                               http_auth_handler_factory,
                               network_delegate,
@@ -51,7 +49,6 @@ bool HttpNetworkLayer::force_spdy_ = false;
 
 HttpNetworkLayer::HttpNetworkLayer(
     ClientSocketFactory* socket_factory,
-    NetworkChangeNotifier* network_change_notifier,
     HostResolver* host_resolver,
     ProxyService* proxy_service,
     SSLConfigService* ssl_config_service,
@@ -59,7 +56,6 @@ HttpNetworkLayer::HttpNetworkLayer(
     HttpNetworkDelegate* network_delegate,
     NetLog* net_log)
     : socket_factory_(socket_factory),
-      network_change_notifier_(network_change_notifier),
       host_resolver_(host_resolver),
       proxy_service_(proxy_service),
       ssl_config_service_(ssl_config_service),
@@ -75,7 +71,6 @@ HttpNetworkLayer::HttpNetworkLayer(
 
 HttpNetworkLayer::HttpNetworkLayer(HttpNetworkSession* session)
     : socket_factory_(ClientSocketFactory::GetDefaultFactory()),
-      network_change_notifier_(NULL),
       ssl_config_service_(NULL),
       session_(session),
       spdy_session_pool_(session->spdy_session_pool()),
@@ -114,15 +109,11 @@ void HttpNetworkLayer::Suspend(bool suspend) {
 HttpNetworkSession* HttpNetworkLayer::GetSession() {
   if (!session_) {
     DCHECK(proxy_service_);
-    SpdySessionPool* spdy_pool = new SpdySessionPool(network_change_notifier_);
-    session_ = new HttpNetworkSession(
-        network_change_notifier_, host_resolver_, proxy_service_,
+    SpdySessionPool* spdy_pool = new SpdySessionPool();
+    session_ = new HttpNetworkSession(host_resolver_, proxy_service_,
         socket_factory_, ssl_config_service_, spdy_pool,
-        http_auth_handler_factory_,
-        network_delegate_,
-        net_log_);
+        http_auth_handler_factory_, network_delegate_, net_log_);
     // These were just temps for lazy-initializing HttpNetworkSession.
-    network_change_notifier_ = NULL;
     host_resolver_ = NULL;
     proxy_service_ = NULL;
     socket_factory_ = NULL;
diff --git a/net/http/http_network_layer.h b/net/http/http_network_layer.h
index 54989410..4a61065 100644
--- a/net/http/http_network_layer.h
+++ b/net/http/http_network_layer.h
@@ -19,7 +19,6 @@ class HttpAuthHandlerFactory;
 class HttpNetworkDelegate;
 class HttpNetworkSession;
 class NetLog;
-class NetworkChangeNotifier;
 class ProxyInfo;
 class ProxyService;
 class SpdySessionPool;
@@ -27,11 +26,11 @@ class SSLConfigService;
 
 class HttpNetworkLayer : public HttpTransactionFactory {
  public:
-  // |socket_factory|, |network_change_notifier|, |proxy_service| and
-  // |host_resolver| must remain valid for the lifetime of HttpNetworkLayer.
+  // |socket_factory|, |proxy_service| and |host_resolver| must remain valid for
+  // the lifetime of HttpNetworkLayer.
   HttpNetworkLayer(ClientSocketFactory* socket_factory,
-                   NetworkChangeNotifier* network_change_notifier,
-                   HostResolver* host_resolver, ProxyService* proxy_service,
+                   HostResolver* host_resolver,
+                   ProxyService* proxy_service,
                    SSLConfigService* ssl_config_service,
                    HttpAuthHandlerFactory* http_auth_handler_factory,
                    HttpNetworkDelegate* network_delegate,
@@ -44,7 +43,6 @@ class HttpNetworkLayer : public HttpTransactionFactory {
   // This function hides the details of how a network layer gets instantiated
   // and allows other implementations to be substituted.
   static HttpTransactionFactory* CreateFactory(
-      NetworkChangeNotifier* network_change_notifier,
       HostResolver* host_resolver,
       ProxyService* proxy_service,
       SSLConfigService* ssl_config_service,
@@ -77,8 +75,6 @@ class HttpNetworkLayer : public HttpTransactionFactory {
   // The factory we will use to create network sockets.
   ClientSocketFactory* socket_factory_;
 
-  NetworkChangeNotifier* network_change_notifier_;
-
   // The host resolver and proxy service that will be used when lazily
   // creating |session_|.
   scoped_refptr<HostResolver> host_resolver_;
diff --git a/net/http/http_network_layer_unittest.cc b/net/http/http_network_layer_unittest.cc
index 9f20943..274d2dc 100644
--- a/net/http/http_network_layer_unittest.cc
+++ b/net/http/http_network_layer_unittest.cc
@@ -16,9 +16,9 @@ class HttpNetworkLayerTest : public PlatformTest {
 };
 
 TEST_F(HttpNetworkLayerTest, CreateAndDestroy) {
-  net::HttpNetworkLayer factory(
-      NULL, NULL, new net::MockHostResolver, net::ProxyService::CreateNull(),
-      new net::SSLConfigServiceDefaults, NULL, NULL, NULL);
+  net::HttpNetworkLayer factory(NULL, new net::MockHostResolver,
+      net::ProxyService::CreateNull(), new net::SSLConfigServiceDefaults, NULL,
+      NULL, NULL);
 
   scoped_ptr<net::HttpTransaction> trans;
   int rv = factory.CreateTransaction(&trans);
@@ -27,9 +27,9 @@ TEST_F(HttpNetworkLayerTest, CreateAndDestroy) {
 }
 
 TEST_F(HttpNetworkLayerTest, Suspend) {
-  net::HttpNetworkLayer factory(
-      NULL, NULL, new net::MockHostResolver, net::ProxyService::CreateNull(),
-      new net::SSLConfigServiceDefaults, NULL, NULL, NULL);
+  net::HttpNetworkLayer factory(NULL, new net::MockHostResolver,
+      net::ProxyService::CreateNull(), new net::SSLConfigServiceDefaults, NULL,
+      NULL, NULL);
 
   scoped_ptr<net::HttpTransaction> trans;
   int rv = factory.CreateTransaction(&trans);
@@ -67,11 +67,9 @@ TEST_F(HttpNetworkLayerTest, GET) {
                                      data_writes, arraysize(data_reads));
   mock_socket_factory.AddSocketDataProvider(&data);
 
-  net::HttpNetworkLayer factory(&mock_socket_factory, NULL,
-                                new net::MockHostResolver,
-                                net::ProxyService::CreateNull(),
-                                new net::SSLConfigServiceDefaults,
-                                NULL, NULL, NULL);
+  net::HttpNetworkLayer factory(&mock_socket_factory, new net::MockHostResolver,
+      net::ProxyService::CreateNull(), new net::SSLConfigServiceDefaults, NULL,
+      NULL, NULL);
 
   TestCompletionCallback callback;
 
diff --git a/net/http/http_network_session.cc b/net/http/http_network_session.cc
index 1083626..ea5a5cf 100644
--- a/net/http/http_network_session.cc
+++ b/net/http/http_network_session.cc
@@ -36,7 +36,6 @@ uint16 g_fixed_https_port = 0;
 }  // namespace
 
 HttpNetworkSession::HttpNetworkSession(
-    NetworkChangeNotifier* network_change_notifier,
     HostResolver* host_resolver,
     ProxyService* proxy_service,
     ClientSocketFactory* client_socket_factory,
@@ -45,18 +44,16 @@ HttpNetworkSession::HttpNetworkSession(
     HttpAuthHandlerFactory* http_auth_handler_factory,
     HttpNetworkDelegate* network_delegate,
     NetLog* net_log)
-    : network_change_notifier_(network_change_notifier),
       // TODO(vandebo) when we've completely converted to pools, the base TCP
       // pool name should get changed to TCP instead of Transport.
-      tcp_pool_histograms_(new ClientSocketPoolHistograms("Transport")),
+    : tcp_pool_histograms_(new ClientSocketPoolHistograms("Transport")),
       http_proxy_pool_histograms_(new ClientSocketPoolHistograms("HTTPProxy")),
       tcp_for_socks_pool_histograms_(
           new ClientSocketPoolHistograms("TCPforSOCKS")),
       socks_pool_histograms_(new ClientSocketPoolHistograms("SOCK")),
-      tcp_socket_pool_(new TCPClientSocketPool(
-          g_max_sockets, g_max_sockets_per_group, tcp_pool_histograms_,
-          host_resolver, client_socket_factory, network_change_notifier_,
-          net_log)),
+      tcp_socket_pool_(new TCPClientSocketPool(g_max_sockets,
+          g_max_sockets_per_group, tcp_pool_histograms_, host_resolver,
+          client_socket_factory, net_log)),
       socket_factory_(client_socket_factory),
       host_resolver_(host_resolver),
       proxy_service_(proxy_service),
@@ -80,14 +77,10 @@ HttpNetworkSession::GetSocketPoolForHTTPProxy(const HostPortPair& http_proxy) {
     return it->second;
 
   std::pair<HTTPProxySocketPoolMap::iterator, bool> ret =
-      http_proxy_socket_pool_.insert(
-          std::make_pair(
-              http_proxy,
-              new TCPClientSocketPool(
-                  g_max_sockets_per_proxy_server, g_max_sockets_per_group,
-                  http_proxy_pool_histograms_, host_resolver_, socket_factory_,
-                  network_change_notifier_,
-                  net_log_)));
+      http_proxy_socket_pool_.insert(std::make_pair(http_proxy,
+          new TCPClientSocketPool(g_max_sockets_per_proxy_server,
+              g_max_sockets_per_group, http_proxy_pool_histograms_,
+              host_resolver_, socket_factory_, net_log_)));
 
   return ret.first->second;
 }
@@ -99,20 +92,14 @@ HttpNetworkSession::GetSocketPoolForSOCKSProxy(
   if (it != socks_socket_pool_.end())
     return it->second;
 
-  std::pair<SOCKSSocketPoolMap::iterator, bool> ret =
-      socks_socket_pool_.insert(
-          std::make_pair(
-              socks_proxy,
-              new SOCKSClientSocketPool(
-                  g_max_sockets_per_proxy_server, g_max_sockets_per_group,
-                  socks_pool_histograms_, host_resolver_,
-                  new TCPClientSocketPool(g_max_sockets_per_proxy_server,
-                                          g_max_sockets_per_group,
-                                          tcp_for_socks_pool_histograms_,
-                                          host_resolver_, socket_factory_,
-                                          network_change_notifier_,
-                                          net_log_),
-                  network_change_notifier_, net_log_)));
+  std::pair<SOCKSSocketPoolMap::iterator, bool> ret = socks_socket_pool_.insert(
+      std::make_pair(socks_proxy, new SOCKSClientSocketPool(
+          g_max_sockets_per_proxy_server, g_max_sockets_per_group,
+          socks_pool_histograms_, host_resolver_,
+          new TCPClientSocketPool(g_max_sockets_per_proxy_server,
+              g_max_sockets_per_group, tcp_for_socks_pool_histograms_,
+              host_resolver_, socket_factory_, net_log_),
+          net_log_)));
 
   return ret.first->second;
 }
diff --git a/net/http/http_network_session.h b/net/http/http_network_session.h
index 1288197..319753c 100644
--- a/net/http/http_network_session.h
+++ b/net/http/http_network_session.h
@@ -28,14 +28,12 @@ class ClientSocketFactory;
 class HttpAuthHandlerFactory;
 class HttpNetworkDelegate;
 class HttpNetworkSessionPeer;
-class NetworkChangeNotifier;
 class SpdySessionPool;
 
 // This class holds session objects used by HttpNetworkTransaction objects.
 class HttpNetworkSession : public base::RefCounted<HttpNetworkSession> {
  public:
   HttpNetworkSession(
-      NetworkChangeNotifier* network_change_notifier,
       HostResolver* host_resolver,
       ProxyService* proxy_service,
       ClientSocketFactory* client_socket_factory,
@@ -113,7 +111,6 @@ class HttpNetworkSession : public base::RefCounted<HttpNetworkSession> {
   HttpAuthCache auth_cache_;
   SSLClientAuthCache ssl_client_auth_cache_;
   HttpAlternateProtocols alternate_protocols_;
-  NetworkChangeNotifier* const network_change_notifier_;
   scoped_refptr<ClientSocketPoolHistograms> tcp_pool_histograms_;
   scoped_refptr<ClientSocketPoolHistograms> http_proxy_pool_histograms_;
   scoped_refptr<ClientSocketPoolHistograms> tcp_for_socks_pool_histograms_;
diff --git a/net/http/http_network_transaction_unittest.cc b/net/http/http_network_transaction_unittest.cc
index 35ba760..dd04773 100644
--- a/net/http/http_network_transaction_unittest.cc
+++ b/net/http/http_network_transaction_unittest.cc
@@ -83,7 +83,7 @@ struct SessionDependencies {
         proxy_service(ProxyService::CreateNull()),
         ssl_config_service(new SSLConfigServiceDefaults),
         http_auth_handler_factory(HttpAuthHandlerFactory::CreateDefault()),
-        spdy_session_pool(new SpdySessionPool(NULL)) {}
+        spdy_session_pool(new SpdySessionPool()) {}
 
   // Custom proxy service dependency.
   explicit SessionDependencies(ProxyService* proxy_service)
@@ -91,7 +91,7 @@ struct SessionDependencies {
         proxy_service(proxy_service),
         ssl_config_service(new SSLConfigServiceDefaults),
         http_auth_handler_factory(HttpAuthHandlerFactory::CreateDefault()),
-        spdy_session_pool(new SpdySessionPool(NULL)) {}
+        spdy_session_pool(new SpdySessionPool()) {}
 
   scoped_refptr<MockHostResolverBase> host_resolver;
   scoped_refptr<ProxyService> proxy_service;
@@ -108,8 +108,7 @@ ProxyService* CreateFixedProxyService(const std::string& proxy) {
 }
 
 HttpNetworkSession* CreateSession(SessionDependencies* session_deps) {
-  return new HttpNetworkSession(NULL,
-                                session_deps->host_resolver,
+  return new HttpNetworkSession(session_deps->host_resolver,
                                 session_deps->proxy_service,
                                 &session_deps->socket_factory,
                                 session_deps->ssl_config_service,
@@ -241,7 +240,8 @@ class CaptureGroupNameSocketPool : public EmulatedClientSocketPool {
  public:
   explicit CaptureGroupNameSocketPool(HttpNetworkSession* session)
       : EmulatedClientSocketPool(0, 0, NULL, session->host_resolver(), NULL,
-                                 NULL, NULL) {}
+                                 NULL) {
+  }
   const std::string last_group_name_received() const {
     return last_group_name_;
   }
@@ -5249,11 +5249,9 @@ TEST_F(HttpNetworkTransactionTest, UseAlternateProtocolForTunneledNpnSpdy) {
 
   CapturingProxyResolver* capturing_proxy_resolver =
       new CapturingProxyResolver();
-  SessionDependencies session_deps(
-      new ProxyService(new ProxyConfigServiceFixed(proxy_config),
-                       capturing_proxy_resolver,
-                       NULL,
-                       NULL));
+  SessionDependencies session_deps(new ProxyService(
+      new ProxyConfigServiceFixed(proxy_config), capturing_proxy_resolver,
+      NULL));
 
   HttpRequestInfo request;
   request.method = "GET";