Fix the issue of undefined-shift in VP8GetBit.

webrtc/modules/video_coding/utility/vp8_header_parser.cc

 /*
  *  Copyright (c) 2015 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.
  */
 #include "webrtc/modules/video_coding/utility/vp8_header_parser.h"
@@ skipping 56 matching lines @@
   br->bits_ = -8;  // To load the very first 8bits.
   br->eof_ = 0;
   VP8LoadNewBytes(br);
 }
 
 // Read a bit with proba 'prob'.
 static int VP8GetBit(VP8BitReader* const br, int prob) {
   uint8_t range = br->range_;
   if (br->bits_ < 0) {
     VP8LoadNewBytes(br);
+    if (br->eof_)
+      return 0;
   }
-
   const int pos = br->bits_;
   const uint8_t split = (range * prob) >> 8;
   const uint8_t value = static_cast<uint8_t>(br->value_ >> pos);
   int bit;
   if (value > split) {
     range -= split + 1;
     br->value_ -= static_cast<uint32_t>(split + 1) << pos;
     bit = 1;
   } else {
     range = split;
@@ skipping 106 matching lines @@
     LOG(LS_WARNING) << "Failed to get QP, end of file reached.";
     return false;
   }
   *qp = base_q0;
   return true;
 }
 
 }  // namespace vp8
 
 }  // namespace webrtc