Revert of Fix to make the start/stop functions for the Rtc Eventlog non-virtual.

webrtc/api/peerconnectioninterface.h

Index: webrtc/api/peerconnectioninterface.h
diff --git a/webrtc/api/peerconnectioninterface.h b/webrtc/api/peerconnectioninterface.h
index c72e2ec8af4a7eb89ad41c4fe71d3b9dc7682a38..e57435559e25c6a1254ad46b801afeb91e73f6ff 100644
--- a/webrtc/api/peerconnectioninterface.h
+++ b/webrtc/api/peerconnectioninterface.h
@@ -494,15 +494,11 @@
   // operation fails the file will be closed. The logging will stop
   // automatically after 10 minutes have passed, or when the StopRtcEventLog
   // function is called.
-  // TODO(ivoc): Make this pure virtual when Chrome is updated.
   virtual bool StartRtcEventLog(rtc::PlatformFile file,
-                                int64_t max_size_bytes) {
-    return false;
-  }
+                                int64_t max_size_bytes) = 0;
 
   // Stops logging the RtcEventLog.
-  // TODO(ivoc): Make this pure virtual when Chrome is updated.
-  virtual void StopRtcEventLog() {}
+  virtual void StopRtcEventLog() = 0;
 
   // Terminates all media and closes the transport.
   virtual void Close() = 0;