Changed the semantics of Buffer::Clear to not alter the capacity

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 162 matching lines @@
   }
 
   // b.Pass() does the same thing as std::move(b).
   // Deprecated; remove in March 2016 (bug 5373).
   RTC_DEPRECATED Buffer&& Pass() { return DEPRECATED_Pass(); }
   Buffer&& DEPRECATED_Pass() {
     assert(IsConsistent());
     return std::move(*this);
   }
 
-  // Resets the buffer to zero size and capacity. Works even if the buffer has
-  // been moved from.
+  // Resets the buffer to zero size without altering capacity. Works even if the
+  // buffer has been moved from.
   void Clear() {
-    data_.reset();
     size_ = 0;
-    capacity_ = 0;
     assert(IsConsistent());
   }
 
   // Swaps two buffers. Also works for buffers that have been moved from.
   friend void swap(Buffer& a, Buffer& b) {
     using std::swap;
     swap(a.size_, b.size_);
     swap(a.capacity_, b.capacity_);
     swap(a.data_, b.data_);
   }
@@ skipping 23 matching lines @@
   }
 
   size_t size_;
   size_t capacity_;
   std::unique_ptr<uint8_t[]> data_;
 };
 
 }  // namespace rtc
 
 #endif  // WEBRTC_BASE_BUFFER_H_