Adding CreateTcpClientSocket without user_agent and proxy_info.

This is part of a larger refactoring:

1) Add new method and provide default implementations for the other
   Create* methods (this CL) so they can be removed downstream.
2) Implement new method in Chromium and remove the overrides of the
   other Create* methods from subclasses of PacketSocketFactory.
3) Remove other Create* methods from PacketSocketFactory and make
   the new Create method pure virtual. Make BasicPacketSocketFactory
   take user_agent and proxy_info in the constructor.
4) Move the slimmed-down packet_socket_factory into api/.

Bug: webrtc:7447
Change-Id: I961fcc4451c9fb2bc7a049b8f57d5894209fd262
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/150941
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Patrik Höglund <phoglund@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29026}

p2p/base/basic_packet_socket_factory.cc

@@ -97,18 +97,6 @@ AsyncPacketSocket* BasicPacketSocketFactory::CreateServerTcpSocket(
   return new AsyncTCPSocket(socket, true);
 }
 
-AsyncPacketSocket* BasicPacketSocketFactory::CreateClientTcpSocket(
-    const SocketAddress& local_address,
-    const SocketAddress& remote_address,
-    const ProxyInfo& proxy_info,
-    const std::string& user_agent,
-    int opts) {
-  PacketSocketTcpOptions tcp_options;
-  tcp_options.opts = opts;
-  return CreateClientTcpSocket(local_address, remote_address, proxy_info,
-                               user_agent, tcp_options);
-}
-
 AsyncPacketSocket* BasicPacketSocketFactory::CreateClientTcpSocket(
     const SocketAddress& local_address,
     const SocketAddress& remote_address,
@@ -200,6 +188,25 @@ AsyncPacketSocket* BasicPacketSocketFactory::CreateClientTcpSocket(
   return tcp_socket;
 }
 
+AsyncPacketSocket* BasicPacketSocketFactory::CreateClientTcpSocket(
+    const SocketAddress& local_address,
+    const SocketAddress& remote_address,
+    const ProxyInfo& proxy_info,
+    const std::string& user_agent,
+    int opts) {
+  PacketSocketTcpOptions tcp_options;
+  tcp_options.opts = opts;
+  return CreateClientTcpSocket(local_address, remote_address, proxy_info,
+                               user_agent, tcp_options);
+}
+
+AsyncPacketSocket* BasicPacketSocketFactory::CreateClientTcpSocket(
+    const SocketAddress& local_address,
+    const SocketAddress& remote_address) {
+  return CreateClientTcpSocket(local_address, remote_address, ProxyInfo(), "",
+                               PacketSocketTcpOptions());
+}
+
 AsyncResolverInterface* BasicPacketSocketFactory::CreateAsyncResolver() {
   return new AsyncResolver();
 }

p2p/base/basic_packet_socket_factory.h

@@ -35,6 +35,9 @@ class BasicPacketSocketFactory : public PacketSocketFactory {
                                            uint16_t min_port,
                                            uint16_t max_port,
                                            int opts) override;
+  AsyncPacketSocket* CreateClientTcpSocket(
+      const SocketAddress& local_address,
+      const SocketAddress& remote_address) override;
   AsyncPacketSocket* CreateClientTcpSocket(const SocketAddress& local_address,
                                            const SocketAddress& remote_address,
                                            const ProxyInfo& proxy_info,

p2p/base/packet_socket_factory.cc

@@ -12,6 +12,8 @@
 
 #include <string>
 
+#include "rtc_base/checks.h"
+
 namespace rtc {
 
 PacketSocketTcpOptions::PacketSocketTcpOptions() = default;
@@ -28,4 +30,21 @@ AsyncPacketSocket* PacketSocketFactory::CreateClientTcpSocket(
                                user_agent, tcp_options.opts);
 }
 
+AsyncPacketSocket* PacketSocketFactory::CreateClientTcpSocket(
+    const SocketAddress& local_address,
+    const SocketAddress& remote_address,
+    const ProxyInfo& proxy_info,
+    const std::string& user_agent,
+    int opts) {
+  RTC_NOTREACHED();
+  return nullptr;
+}
+
+AsyncPacketSocket* PacketSocketFactory::CreateClientTcpSocket(
+    const SocketAddress& local_address,
+    const SocketAddress& remote_address) {
+  RTC_NOTREACHED();
+  return nullptr;
+}
+
 }  // namespace rtc

p2p/base/packet_socket_factory.h

@@ -14,14 +14,16 @@
 #include <string>
 #include <vector>
 
-#include "rtc_base/constructor_magic.h"
 #include "rtc_base/proxy_info.h"
-#include "rtc_base/ssl_certificate.h"
 #include "rtc_base/system/rtc_export.h"
 
 namespace rtc {
 
-// This structure contains options required to create TCP packet sockets.
+class SSLCertificateVerifier;
+class AsyncPacketSocket;
+class AsyncResolverInterface;
+
+// TODO(bugs.webrtc.org/7447): move this to basic_packet_socket_factory.
 struct PacketSocketTcpOptions {
   PacketSocketTcpOptions();
   ~PacketSocketTcpOptions();
@@ -30,13 +32,11 @@ struct PacketSocketTcpOptions {
   std::vector<std::string> tls_alpn_protocols;
   std::vector<std::string> tls_elliptic_curves;
   // An optional custom SSL certificate verifier that an API user can provide to
-  // inject their own certificate verification logic.
+  // inject their own certificate verification logic (not available to users
+  // outside of the WebRTC repo).
   SSLCertificateVerifier* tls_cert_verifier = nullptr;
 };
 
-class AsyncPacketSocket;
-class AsyncResolverInterface;
-
 class RTC_EXPORT PacketSocketFactory {
  public:
   enum Options {
@@ -63,19 +63,21 @@ class RTC_EXPORT PacketSocketFactory {
       uint16_t max_port,
       int opts) = 0;
 
-  // TODO(deadbeef): |proxy_info| and |user_agent| should be set
-  // per-factory and not when socket is created.
+  // TODO(bugs.webrtc.org/7447): This should be the only CreateClientTcpSocket
+  // implementation left; the two other are deprecated.
+  virtual AsyncPacketSocket* CreateClientTcpSocket(
+      const SocketAddress& local_address,
+      const SocketAddress& remote_address);
+
+  // TODO(bugs.webrtc.org/7447): Deprecated, about to be removed.
   virtual AsyncPacketSocket* CreateClientTcpSocket(
       const SocketAddress& local_address,
       const SocketAddress& remote_address,
       const ProxyInfo& proxy_info,
       const std::string& user_agent,
-      int opts) = 0;
+      int opts);
 
-  // TODO(deadbeef): |proxy_info|, |user_agent| and |tcp_options| should
-  // be set per-factory and not when socket is created.
-  // TODO(deadbeef): Implement this method in all subclasses (namely those in
-  // Chromium), make pure virtual, and remove the old CreateClientTcpSocket.
+  // TODO(bugs.webrtc.org/7447): Deprecated, about to be removed.
   virtual AsyncPacketSocket* CreateClientTcpSocket(
       const SocketAddress& local_address,
       const SocketAddress& remote_address,
@@ -86,7 +88,8 @@ class RTC_EXPORT PacketSocketFactory {
   virtual AsyncResolverInterface* CreateAsyncResolver() = 0;
 
  private:
-  RTC_DISALLOW_COPY_AND_ASSIGN(PacketSocketFactory);
+  PacketSocketFactory(const PacketSocketFactory&) = delete;
+  PacketSocketFactory& operator=(const PacketSocketFactory&) = delete;
 };
 
 }  // namespace rtc