Add support for GCM cipher suites from RFC 7714.

talk/app/webrtc/peerconnectionfactory.h

Index: talk/app/webrtc/peerconnectionfactory.h
diff --git a/talk/app/webrtc/peerconnectionfactory.h b/talk/app/webrtc/peerconnectionfactory.h
index cad89d4ab5185a48ee1c36248d3325594afcb51a..4122b52b54914259bed5a7a73f3528f4536c2c49 100644
--- a/talk/app/webrtc/peerconnectionfactory.h
+++ b/talk/app/webrtc/peerconnectionfactory.h
@@ -51,9 +51,7 @@ typedef rtc::RefCountedObject<DtlsIdentityStoreImpl>
 
 class PeerConnectionFactory : public PeerConnectionFactoryInterface {
  public:
-  virtual void SetOptions(const Options& options) {
-    options_ = options;
-  }
+  void SetOptions(const Options& options) override;
 
   // webrtc::PeerConnectionFactoryInterface override;
   // TODO(deadbeef): Get rid of this overload once clients are moved to the