Add [c]begin() and [c]end() member functions to rtc::Buffer

webrtc/base/buffer.h

 /*
  *  Copyright 2004 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 161 matching lines @@
   T& operator[](size_t index) {
     RTC_DCHECK_LT(index, size_);
     return data()[index];
   }
 
   T operator[](size_t index) const {
     RTC_DCHECK_LT(index, size_);
     return data()[index];
   }
 
+  T* begin() { return data(); }
+  T* end() { return data() + size(); }
+  const T* begin() const { return data(); }
+  const T* end() const { return data() + size(); }
+  const T* cbegin() const { return data(); }
+  const T* cend() const { return data() + size(); }
+
   // The SetData functions replace the contents of the buffer. They accept the
   // same input types as the constructors.
   template <typename U,
             typename std::enable_if<
                 internal::BufferCompat<T, U>::value>::type* = nullptr>
   void SetData(const U* data, size_t size) {
     RTC_DCHECK(IsConsistent());
     size_ = 0;
     AppendData(data, size);
   }
@@ skipping 173 matching lines @@
   size_t capacity_;
   std::unique_ptr<T[]> data_;
 };
 
 // By far the most common sort of buffer.
 using Buffer = BufferT<uint8_t>;
 
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_BUFFER_H_