Revert of Change WebRTC SslCipher to be exposed as number only.

talk/app/webrtc/peerconnectioninterface.h

Index: talk/app/webrtc/peerconnectioninterface.h
diff --git a/talk/app/webrtc/peerconnectioninterface.h b/talk/app/webrtc/peerconnectioninterface.h
index d3d0d9e66710d8a97cdf3b24529c2f3ac8c59085..f301bafdff54f672f3f3da501d8965b934e78405 100644
--- a/talk/app/webrtc/peerconnectioninterface.h
+++ b/talk/app/webrtc/peerconnectioninterface.h
@@ -137,16 +137,11 @@
                                     int counter,
                                     int counter_max) {}
 
-  // This is used to handle sparse counters like SSL cipher suites.
-  // TODO(guoweis): Remove the implementation once the dependency's interface
-  // definition is updated.
-  virtual void IncrementSparseEnumCounter(PeerConnectionEnumCounterType type,
-                                          int counter) {
-    IncrementEnumCounter(type, counter, 0 /* Ignored */);
-  }
-
   virtual void AddHistogramSample(PeerConnectionMetricsName type,
                                   int value) = 0;
+  // TODO(jbauch): Make method abstract when it is implemented by Chromium.
+  virtual void AddHistogramSample(PeerConnectionMetricsName type,
+                                  const std::string& value) {}
 
  protected:
   virtual ~MetricsObserverInterface() {}