Enable cpplint and fix cpplint errors in webrtc/api

webrtc/api/mediaconstraintsinterface.cc

 /*
  *  Copyright 2013 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 52 matching lines @@
 template <typename T>
 void ConstraintToOptional(const webrtc::MediaConstraintsInterface* constraints,
                           const std::string& key,
                           rtc::Optional<T>* value_out) {
   T value;
   bool present = FindConstraint<T>(constraints, key, &value, nullptr);
   if (present) {
     *value_out = rtc::Optional<T>(value);
   }
 }
-}
+}  // namespace
 
 namespace webrtc {
 
 const char MediaConstraintsInterface::kValueTrue[] = "true";
 const char MediaConstraintsInterface::kValueFalse[] = "false";
 
 // Constraints declared as static members in mediastreaminterface.h
 // Specified by draft-alvestrand-constraints-resolution-00b
 const char MediaConstraintsInterface::kMinAspectRatio[] = "minAspectRatio";
 const char MediaConstraintsInterface::kMaxAspectRatio[] = "maxAspectRatio";
@@ skipping 182 matching lines @@
       constraints, MediaConstraintsInterface::kAudioNetworkAdaptorConfig,
       &options->audio_network_adaptor_config);
   // When |kAudioNetworkAdaptorConfig| is defined, it both means that audio
   // network adaptor is desired, and provides the config string.
   if (options->audio_network_adaptor_config) {
     options->audio_network_adaptor = rtc::Optional<bool>(true);
   }
 }
 
 }  // namespace webrtc