Handle case where UDP packet contains multiple DTLS records.

webrtc/p2p/base/fakeicetransport.h

Index: webrtc/p2p/base/fakeicetransport.h
diff --git a/webrtc/p2p/base/fakeicetransport.h b/webrtc/p2p/base/fakeicetransport.h
index 2b0662f8561cde3f69fd713f8ae0ea44f26debec..357668f44f8ec224c0e4d9076f44ed58ce15f623 100644
--- a/webrtc/p2p/base/fakeicetransport.h
+++ b/webrtc/p2p/base/fakeicetransport.h
@@ -161,6 +161,9 @@ class FakeIceTransport : public IceTransportInternal {
   // Fake PacketTransportInternal implementation.
   bool writable() const override { return writable_; }
   bool receiving() const override { return receiving_; }
+  // If combine is enabled, two incoming packets will be combined into one

[Taylor Brandstetter, 2017/07/06 22:06:11]

This comment is a little misleading, since all the packets here are outgoing.

[joachim, 2017/07/07 16:13:00]

Changed.

+  // outgoing packet.
+  void set_combine(bool combine) { combine_ = combine; }

[Taylor Brandstetter, 2017/07/06 22:06:11]

nit: Making this name more descriptive, like "combine_outgoing_packets",
wouldn't hurt.

[joachim, 2017/07/07 16:13:00]

Done.

   int SendPacket(const char* data,
                  size_t len,
                  const rtc::PacketOptions& options,
@@ -168,14 +171,18 @@ class FakeIceTransport : public IceTransportInternal {
     if (!dest_) {
       return -1;
     }
-    rtc::CopyOnWriteBuffer packet(data, len);
-    if (async_) {
-      invoker_.AsyncInvokeDelayed<void>(
-          RTC_FROM_HERE, rtc::Thread::Current(),
-          rtc::Bind(&FakeIceTransport::SendPacketInternal, this, packet),
-          async_delay_ms_);
-    } else {
-      SendPacketInternal(packet);
+
+    send_packet_.AppendData(data, len);
+    if (!combine_ || send_packet_.size() > len) {
+      rtc::CopyOnWriteBuffer packet(std::move(send_packet_));
+      if (async_) {
+        invoker_.AsyncInvokeDelayed<void>(
+            RTC_FROM_HERE, rtc::Thread::Current(),
+            rtc::Bind(&FakeIceTransport::SendPacketInternal, this, packet),
+            async_delay_ms_);
+      } else {
+        SendPacketInternal(packet);
+      }
     }
     rtc::SentPacket sent_packet(options.packet_id, rtc::TimeMillis());
     SignalSentPacket(this, sent_packet);
@@ -233,6 +240,8 @@ class FakeIceTransport : public IceTransportInternal {
   bool had_connection_ = false;
   bool writable_ = false;
   bool receiving_ = false;
+  bool combine_ = false;
+  rtc::CopyOnWriteBuffer send_packet_;
 };
 
 }  // namespace cricket