Merge 84251, 85083, 85188, 85375, 77501.

src/net/socket/tcp_client_socket_pool.h

Index: src/net/socket/tcp_client_socket_pool.h
===================================================================
--- src/net/socket/tcp_client_socket_pool.h	(revision 85857)
+++ src/net/socket/tcp_client_socket_pool.h	(working copy)
@@ -47,7 +47,13 @@
 };
 
 // TCPConnectJob handles the host resolution necessary for socket creation
-// and the tcp connect.
+// and the transport (likely TCP) connect. TCPConnectJob also has fallback
+// logic for IPv6 connect() timeouts (which may happen due to networks / routers
+// with broken IPv6 support). Those timeouts take 20s, so rather than make the
+// user wait 20s for the timeout to fire, we use a fallback timer
+// (kIPv6FallbackTimerInMs) and start a connect() to a IPv4 address if the timer
+// fires. Then we race the IPv4 connect() against the IPv6 connect() (which has
+// a headstart) and return the one that completes first to the socket pool.
 class TCPConnectJob : public ConnectJob {
  public:
   TCPConnectJob(const std::string& group_name,
@@ -62,6 +68,15 @@
   // ConnectJob methods.
   virtual LoadState GetLoadState() const;
 
+  // Makes |addrlist| start with an IPv4 address if |addrlist| contains any
+  // IPv4 address.
+  //
+  // WARNING: this method should only be used to implement the prefer-IPv4
+  // hack.  It is a public method for the unit tests.
+  static void MakeAddrListStartWithIPv4(AddressList* addrlist);
+
+  static const int kIPv6FallbackTimerInMs;
+
  private:
   enum State {
     STATE_RESOLVE_HOST,
@@ -81,6 +96,10 @@
   int DoTCPConnect();
   int DoTCPConnectComplete(int result);
 
+  // Not part of the state machine.
+  void DoIPv6FallbackTCPConnect();
+  void DoIPv6FallbackTCPConnectComplete(int result);
+
   // Begins the host resolution and the TCP connect.  Returns OK on success
   // and ERR_IO_PENDING if it cannot immediately service the request.
   // Otherwise, it returns a net error code.
@@ -99,6 +118,14 @@
   // The time the connect was started (after DNS finished).
   base::TimeTicks connect_start_time_;
 
+  scoped_ptr<ClientSocket> transport_socket_;
+
+  scoped_ptr<ClientSocket> fallback_transport_socket_;
+  scoped_ptr<AddressList> fallback_addresses_;
+  CompletionCallbackImpl<TCPConnectJob> fallback_callback_;
+  base::TimeTicks fallback_connect_start_time_;
+  base::OneShotTimer<TCPConnectJob> fallback_timer_;
+
   DISALLOW_COPY_AND_ASSIGN(TCPConnectJob);
 };