Optimize ParseRbsp method in H264 bitstream parser.

webrtc/common_video/h264/sps_parser.cc

Index: webrtc/common_video/h264/sps_parser.cc
diff --git a/webrtc/common_video/h264/sps_parser.cc b/webrtc/common_video/h264/sps_parser.cc
index 86a39de83f522aaa8796c617650e1f1606a4a33e..9f61de9fc793ca870352cb5bdaefaad795adc088 100644
--- a/webrtc/common_video/h264/sps_parser.cc
+++ b/webrtc/common_video/h264/sps_parser.cc
@@ -11,6 +11,7 @@
 #include "webrtc/common_video/h264/sps_parser.h"
 
 #include <memory>
+#include <vector>
 
 #include "webrtc/common_video/h264/h264_common.h"
 #include "webrtc/base/bitbuffer.h"
@@ -33,8 +34,8 @@ namespace webrtc {
 // Unpack RBSP and parse SPS state from the supplied buffer.
 rtc::Optional<SpsParser::SpsState> SpsParser::ParseSps(const uint8_t* data,
                                                        size_t length) {
-  std::unique_ptr<rtc::Buffer> unpacked_buffer = H264::ParseRbsp(data, length);
-  rtc::BitBuffer bit_buffer(unpacked_buffer->data(), unpacked_buffer->size());
+  std::vector<uint8_t> unpacked_buffer = H264::ParseRbsp(data, length);
+  rtc::BitBuffer bit_buffer(unpacked_buffer.data(), unpacked_buffer.size());
   return ParseSpsUpToVui(&bit_buffer);
 }