Delete deprecated metod RtpRtcp::SetMaxTransferUnit.

Deprecated since cl https://codereview.webrtc.org/2589743002

BUG=webrtc:6847

Review-Url: https://codereview.webrtc.org/3006413002
Cr-Commit-Position: refs/heads/master@{#19878}
diff --git a/modules/rtp_rtcp/include/rtp_rtcp.h b/modules/rtp_rtcp/include/rtp_rtcp.h
index 8ac8999..8d77a87 100644
--- a/modules/rtp_rtcp/include/rtp_rtcp.h
+++ b/modules/rtp_rtcp/include/rtp_rtcp.h
@@ -116,14 +116,6 @@
   // Sender
   // **************************************************************************
 
-  // TODO(nisse): Deprecated. Kept temporarily, as an alias for the
-  // new function which has slighly different semantics. Delete as
-  // soon as known applications are updated.
-  virtual int32_t SetMaxTransferUnit(uint16_t size) {
-    SetMaxRtpPacketSize(size);
-    return 0;
-  }
-
   // Sets the maximum size of an RTP packet, including RTP headers.
   virtual void SetMaxRtpPacketSize(size_t size) = 0;