Fix for fuzzer bug.

webrtc/modules/audio_coding/neteq/decision_logic_normal.cc

 /*
  *  Copyright (c) 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 79 matching lines @@
 Operations DecisionLogicNormal::CngOperation(Modes prev_mode,
                                              uint32_t target_timestamp,
                                              uint32_t available_timestamp,
                                              size_t generated_noise_samples) {
   // Signed difference between target and available timestamp.
   int32_t timestamp_diff = static_cast<int32_t>(
       static_cast<uint32_t>(generated_noise_samples + target_timestamp) -
       available_timestamp);
   int32_t optimal_level_samp = static_cast<int32_t>(
       (delay_manager_->TargetLevel() * packet_length_samples_) >> 8);
-  int32_t excess_waiting_time_samp = -timestamp_diff - optimal_level_samp;
+  const int64_t excess_waiting_time_samp =
+      -static_cast<int64_t>(timestamp_diff) - optimal_level_samp;
 
   if (excess_waiting_time_samp > optimal_level_samp / 2) {
     // The waiting time for this packet will be longer than 1.5
     // times the wanted buffer delay. Apply fast-forward to cut the
     // waiting time down to the optimal.
-    noise_fast_forward_ += excess_waiting_time_samp;
-    timestamp_diff += excess_waiting_time_samp;
+    noise_fast_forward_ = rtc::dchecked_cast<size_t>(noise_fast_forward_ +
+                                                     excess_waiting_time_samp);
+    timestamp_diff =
+        rtc::saturated_cast<int32_t>(timestamp_diff + excess_waiting_time_samp);
   }
 
   if (timestamp_diff < 0 && prev_mode == kModeRfc3389Cng) {
     // Not time to play this packet yet. Wait another round before using this
     // packet. Keep on playing CNG from previous CNG parameters.
     return kRfc3389CngNoPacket;
   } else {
     // Otherwise, go for the CNG packet now.
     noise_fast_forward_ = 0;
     return kRfc3389Cng;
@@ skipping 112 matching lines @@
 bool DecisionLogicNormal::PacketTooEarly(uint32_t timestamp_leap) const {
   return timestamp_leap >
       static_cast<uint32_t>(output_size_samples_ * num_consecutive_expands_);
 }
 
 bool DecisionLogicNormal::MaxWaitForPacket() const {
   return num_consecutive_expands_ >= kMaxWaitForPacket;
 }
 
 }  // namespace webrtc