Add support for GCM cipher suites from RFC 7714.

webrtc/p2p/base/faketransportcontroller.h

Index: webrtc/p2p/base/faketransportcontroller.h
diff --git a/webrtc/p2p/base/faketransportcontroller.h b/webrtc/p2p/base/faketransportcontroller.h
index 251a0c681aa448bee449937bd43f7ae0f1d1a508..5fd0495f3595bd29b5b0d1de2cdc1ec9620404bd 100644
--- a/webrtc/p2p/base/faketransportcontroller.h
+++ b/webrtc/p2p/base/faketransportcontroller.h
@@ -311,6 +311,13 @@ class FakeTransportChannel : public TransportChannelImpl,
     return ssl_max_version_;
   }
 
+  void set_enable_gcm_ciphers(bool enable) {
+    enable_gcm_ciphers_ = enable;
+  }
+  bool IsEnableGcmCiphers() const override {
+    return enable_gcm_ciphers_;
+  }
+
  private:
   enum State { STATE_INIT, STATE_CONNECTING, STATE_CONNECTED };
   Transport* transport_;
@@ -333,6 +340,7 @@ class FakeTransportChannel : public TransportChannelImpl,
   std::string remote_ice_pwd_;
   IceMode remote_ice_mode_ = ICEMODE_FULL;
   rtc::SSLProtocolVersion ssl_max_version_ = rtc::SSL_PROTOCOL_DTLS_10;
+  bool enable_gcm_ciphers_ = false;
   rtc::SSLFingerprint dtls_fingerprint_;
   rtc::SSLRole ssl_role_ = rtc::SSL_CLIENT;
   size_t connection_count_ = 0;
@@ -405,6 +413,16 @@ class FakeTransport : public Transport {
   rtc::SSLProtocolVersion ssl_max_protocol_version() const {
     return ssl_max_version_;
   }
+  bool SetEnableGcmCiphers(bool enable) override {
+    enable_gcm_ciphers_ = enable;
+    for (const auto& kv : channels_) {
+      kv.second->set_enable_gcm_ciphers(enable_gcm_ciphers_);
+    }
+    return true;
+  }
+  bool enable_gcm_ciphers() const {
+    return enable_gcm_ciphers_;
+  }
 
   using Transport::local_description;
   using Transport::remote_description;
@@ -417,6 +435,7 @@ class FakeTransport : public Transport {
     FakeTransportChannel* channel =
         new FakeTransportChannel(this, name(), component);
     channel->set_ssl_max_protocol_version(ssl_max_version_);
+    channel->set_enable_gcm_ciphers(enable_gcm_ciphers_);
     channel->SetAsync(async_);
     SetChannelDestination(component, channel);
     channels_[component] = channel;
@@ -454,6 +473,7 @@ class FakeTransport : public Transport {
   bool async_ = false;
   rtc::scoped_refptr<rtc::RTCCertificate> certificate_;
   rtc::SSLProtocolVersion ssl_max_version_ = rtc::SSL_PROTOCOL_DTLS_10;
+  bool enable_gcm_ciphers_ = false;
 };
 
 // Fake TransportController class, which can be passed into a BaseChannel object