Add comments for struct members that were changed from size_t to uin32_t or uint64_t for IPC safety.

media/cast/sender/frame_sender.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/cast/sender/frame_sender.h"
 
 #include <algorithm>
 #include <limits>
 #include <utility>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/numerics/safe_conversions.h"
 #include "base/trace_event/trace_event.h"
 #include "media/cast/cast_defines.h"
 #include "media/cast/constants.h"
 #include "media/cast/sender/sender_encoded_frame.h"
 
 namespace media {
 namespace cast {
 namespace {
 
 const int kMinSchedulingDelayMs = 1;
@@ skipping 209 matching lines @@
 
   VLOG_IF(1, !is_audio_ && encoded_frame->dependency == EncodedFrame::KEY)
       << SENDER_SSRC << "Sending encoded key frame, id=" << frame_id;
 
   scoped_ptr<FrameEvent> encode_event(new FrameEvent());
   encode_event->timestamp = encoded_frame->encode_completion_time;
   encode_event->type = FRAME_ENCODED;
   encode_event->media_type = is_audio_ ? AUDIO_EVENT : VIDEO_EVENT;
   encode_event->rtp_timestamp = encoded_frame->rtp_timestamp;
   encode_event->frame_id = frame_id;
-  encode_event->size = encoded_frame->data.size();
+  encode_event->size = base::checked_cast<uint32_t>(encoded_frame->data.size());
   encode_event->key_frame = encoded_frame->dependency == EncodedFrame::KEY;
   encode_event->target_bitrate = requested_bitrate_before_encode;
   encode_event->encoder_cpu_utilization = encoded_frame->deadline_utilization;
   encode_event->idealized_bitrate_utilization =
       encoded_frame->lossy_utilization;
   cast_environment_->logger()->DispatchFrameEvent(std::move(encode_event));
 
   RecordLatestFrameTimestamps(frame_id,
                               encoded_frame->reference_time,
                               encoded_frame->rtp_timestamp);
@@ skipping 167 matching lines @@
     VLOG(1) << SENDER_SSRC << "Dropping: In-flight duration would be too high.";
     return true;
   }
 
   // Next frame is accepted.
   return false;
 }
 
 }  // namespace cast
 }  // namespace media