Fix a bug in webrtc::ByteReader

webrtc/modules/rtp_rtcp/source/byte_io.h

 /*
  *  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 292 matching lines @@
     data[1] = val >> 8;
   }
 };
 
 // Specializations for four byte words.
 template <typename T>
 class ByteReader<T, 4, false> {
  public:
   static T ReadBigEndian(const uint8_t* data) {
     static_assert(sizeof(T) >= 4, kSizeErrorMsg);
-    return (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | data[3];
+    return (Get(data, 0) << 24) | (Get(data, 1) << 16) | (Get(data, 2) << 8) |
+           Get(data, 3);
   }
 
   static T ReadLittleEndian(const uint8_t* data) {
     static_assert(sizeof(T) >= 4, kSizeErrorMsg);
-    return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24);
+    return Get(data, 0) | (Get(data, 1) << 8) | (Get(data, 2) << 16) |
+           (Get(data, 3) << 24);
+  }
+
+ private:
+  inline static T Get(const uint8_t* data, unsigned int index) {
+    return static_cast<T>(data[index]);
   }
 };
 
 // Specializations for four byte words.
 template <typename T>
 class ByteWriter<T, 4, false> {
  public:
   static void WriteBigEndian(uint8_t* data, T val) {
     static_assert(sizeof(T) >= 4, kSizeErrorMsg);
     data[0] = val >> 24;
@@ skipping 63 matching lines @@
     data[4] = val >> 32;
     data[5] = val >> 40;
     data[6] = val >> 48;
     data[7] = val >> 56;
   }
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_BYTE_IO_H_