Make PacketTransportInternal inherit from PacketTransportInterface.

Was just overlooked in an earlier CL.

BUG=webrtc:7013
TBR=pthatcher@webrtc.org

Review-Url: https://codereview.webrtc.org/2806463003
Cr-Commit-Position: refs/heads/master@{#17579}

webrtc/api/ortc/udptransportinterface.h

@@ -27,7 +27,7 @@ namespace webrtc {
 //
 // Calling SetRemoteAddress sets the destination of outgoing packets; without a
 // destination, packets can't be sent, but they can be received.
-class UdpTransportInterface : virtual public PacketTransportInterface {
+class UdpTransportInterface : public virtual PacketTransportInterface {
  public:
   // Get the address of the socket allocated for this transport.
   virtual rtc::SocketAddress GetLocalAddress() const = 0;

webrtc/p2p/base/fakepackettransport.h

@@ -21,8 +21,7 @@
 namespace rtc {
 
 // Used to simulate a packet-based transport.
-class FakePacketTransport : public PacketTransportInternal,
-                            public webrtc::PacketTransportInterface {
+class FakePacketTransport : public PacketTransportInternal {
  public:
   explicit FakePacketTransport(const std::string& debug_name)
       : debug_name_(debug_name) {}
@@ -87,9 +86,6 @@ class FakePacketTransport : public PacketTransportInternal,
   bool GetOption(Socket::Option opt, int* value) override { return true; }
   int GetError() override { return 0; }
 
- protected:
-  PacketTransportInternal* GetInternal() override { return this; }
-
  private:
   void set_writable(bool writable) {
     if (writable_ == writable) {

webrtc/p2p/base/packettransportinternal.h

@@ -15,6 +15,7 @@
 #include <vector>
 
 // This is included for PacketOptions.
+#include "webrtc/api/ortc/packettransportinterface.h"
 #include "webrtc/base/asyncpacketsocket.h"
 #include "webrtc/base/sigslot.h"
 #include "webrtc/base/socket.h"
@@ -28,7 +29,8 @@ struct PacketOptions;
 struct PacketTime;
 struct SentPacket;
 
-class PacketTransportInternal : public sigslot::has_slots<> {
+class PacketTransportInternal : public virtual webrtc::PacketTransportInterface,
+                                public sigslot::has_slots<> {
  public:
   // Identify the object for logging and debug purpose.
   virtual std::string debug_name() const = 0;
@@ -88,6 +90,9 @@ class PacketTransportInternal : public sigslot::has_slots<> {
   // Signalled each time a packet is sent on this channel.
   sigslot::signal2<PacketTransportInternal*, const rtc::SentPacket&>
       SignalSentPacket;
+
+ protected:
+  PacketTransportInternal* GetInternal() override { return this; }
 };
 
 }  // namespace rtc