Fix valgrind complaint on uninitialized value

webrtc/modules/video_coding/utility/frame_dropper.cc

 /*
  *  Copyright (c) 2011 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 55 matching lines @@
   key_frame_ratio_.Reset(kDefaultKeyFrameRatioAlpha);
   key_frame_ratio_.Apply(1.0f, kDefaultKeyFrameRatioValue);
   delta_frame_size_avg_kbits_.Reset(kDefaultFrameSizeAlpha);
 
   accumulator_ = 0.0f;
   accumulator_max_ = kDefaultTargetBitrateKbps / 2;
   target_bitrate_ = kDefaultTargetBitrateKbps;
   incoming_frame_rate_ = kDefaultIncomingFrameRate;
 
   large_frame_accumulation_count_ = 0;
+  large_frame_accumulation_chunk_size_ = 0;
   large_frame_accumulation_spread_ = 0.5 * kDefaultIncomingFrameRate;
 
   drop_next_ = false;
   drop_ratio_.Reset(0.9f);
   drop_ratio_.Apply(0.0f, 0.0f);
   drop_count_ = 0;
   was_below_max_ = true;
 }
 
 void FrameDropper::Enable(bool enable) {
@@ skipping 184 matching lines @@
 // This is a temporary fix for screencasting where very large frames from
 // encoder will cause very slow response (too many frame drops).
 // TODO(isheriff): Remove this now that large delta frames are also spread out ?
 void FrameDropper::CapAccumulator() {
   float max_accumulator = target_bitrate_ * kAccumulatorCapBufferSizeSecs;
   if (accumulator_ > max_accumulator) {
     accumulator_ = max_accumulator;
   }
 }
 }  // namespace webrtc