public void addCapabilities(String capabilityName, String capabilityValue) {
    this.extraCapabilities.put(capabilityName, capabilityValue);
  }
add new capability name/value pair to browser

@param capabilityName capability name
@param capabilityValue capability value
KITE-Framework/src/main/java/org/webrtc/kite/config/client/Capability.java