Fix missing-break-fallthrough warning.

webrtc/modules/video_coding/packet_buffer.cc

 /*
  *  Copyright (c) 2016 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 189 matching lines @@
     ++seq_num;
   }
   return true;
 }
 
 void PacketBuffer::ManageFrame(std::unique_ptr<RtpFrameObject> frame) {
   size_t start_index = frame->first_seq_num() % size_;
   VideoCodecType codec_type = data_buffer_[start_index].codec;
 
   switch (codec_type) {
-    case kVideoCodecULPFEC :
-    case kVideoCodecRED :
-    case kVideoCodecUnknown : {
+    case kVideoCodecULPFEC:
+    case kVideoCodecRED:
+    case kVideoCodecUnknown:
       RTC_NOTREACHED();
-    }
-    case kVideoCodecVP8 : {
+      break;
+    case kVideoCodecVP8:
       ManageFrameVp8(std::move(frame));
       break;
-    }
-    case kVideoCodecVP9 : {
+    case kVideoCodecVP9:
       // TODO(philipel): ManageFrameVp9(std::move(frame));
       break;
-    }
-    case kVideoCodecH264 :
-    case kVideoCodecI420 :
-    case kVideoCodecGeneric :
-    default : {
+    case kVideoCodecH264:
+    case kVideoCodecI420:
+    case kVideoCodecGeneric:
       ManageFrameGeneric(std::move(frame));
-    }
+      break;
   }
 }
 
 void PacketBuffer::RetryStashedFrames() {
   size_t num_stashed_frames = stashed_frames_.size();
 
   // Clean up stashed frames if there are too many.
   while (stashed_frames_.size() > kMaxStashedFrames)
     stashed_frames_.pop();
 
@@ skipping 220 matching lines @@
   last_seq_num_gop_.clear();
   while (!stashed_frames_.empty())
     stashed_frames_.pop();
   not_yet_received_frames_.clear();
 
   first_packet_received_ = false;
 }
 
 }  // namespace video_coding
 }  // namespace webrtc