Remove final from rtc::Buffer.

webrtc/base/buffer.h

Index: webrtc/base/buffer.h
diff --git a/webrtc/base/buffer.h b/webrtc/base/buffer.h
index 8071701d5a148b0262f192d9fb015d494acb1356..7b9402b5113904ea184d1df50826679750ca9c91 100644
--- a/webrtc/base/buffer.h
+++ b/webrtc/base/buffer.h
@@ -44,7 +44,7 @@ struct ByteType {
 
 // Basic buffer class, can be grown and shrunk dynamically.
 // Unlike std::string/vector, does not initialize data when expanding capacity.
-class Buffer final {
+class Buffer {
  public:
   Buffer();                   // An empty buffer.
   Buffer(const Buffer& buf);  // Copy size and contents of an existing buffer.