Add UMA stats for audio/video containers.

media/base/bit_reader.h

 // Copyright (c) 2012 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.
 
 #ifndef MEDIA_BASE_BIT_READER_H_
 #define MEDIA_BASE_BIT_READER_H_
 
 #include <sys/types.h>
 
 #include "base/basictypes.h"
@@ skipping 19 matching lines @@
   // return false unless |num_bits| is 0. The type |T| has to be a primitive
   // integer type.
   template<typename T> bool ReadBits(int num_bits, T *out) {
     DCHECK_LE(num_bits, static_cast<int>(sizeof(T) * 8));
     uint64 temp;
     bool ret = ReadBitsInternal(num_bits, &temp);
     *out = static_cast<T>(temp);
     return ret;
   }
 
+  // Skip |num_bits| next bits from stream. Return false if the given number of
+  // bits cannot be skipped (not enough bits in the stream), true otherwise.
+  // When return false, the stream will enter a state where further ReadBits/
+  // SkipBits operations will always return false unless |num_bits| is 0.
+  bool SkipBits(int num_bits);
+
   // Returns the number of bits available for reading.
   int bits_available() const;
 
  private:
   // Help function used by ReadBits to avoid inlining the bit reading logic.
   bool ReadBitsInternal(int num_bits, uint64* out);
 
   // Advance to the next byte, loading it into curr_byte_.
   // If the num_remaining_bits_in_curr_byte_ is 0 after this function returns,
   // the stream has reached the end.
@@ skipping 12 matching lines @@
   // Number of bits remaining in curr_byte_
   int num_remaining_bits_in_curr_byte_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BitReader);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_BIT_READER_H_