Revert of Don't use barcodes in ProtocolPerfTests

remoting/test/scroll_frame_generator.h

Index: remoting/test/scroll_frame_generator.h
diff --git a/remoting/test/scroll_frame_generator.h b/remoting/test/scroll_frame_generator.h
index e76059713c3b1ad584dedce6d8eb852823d3704e..762ad7bd0c19dcf80cbd9c2f7d8b66d6f4e6505a 100644
--- a/remoting/test/scroll_frame_generator.h
+++ b/remoting/test/scroll_frame_generator.h
@@ -10,29 +10,32 @@
 
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
-#include "remoting/protocol/input_event_timestamps.h"
 #include "third_party/webrtc/modules/desktop_capture/desktop_capturer.h"
 
 namespace remoting {
 namespace test {
 
-class ScrollFrameGenerator : public protocol::InputEventTimestampsSource {
+class ScrollFrameGenerator
+    : public base::RefCountedThreadSafe<ScrollFrameGenerator> {
  public:
   ScrollFrameGenerator();
 
   std::unique_ptr<webrtc::DesktopFrame> GenerateFrame(
       webrtc::SharedMemoryFactory* shared_memory_factory);
 
-  // InputEventTimestampsSource interface.
-  protocol::InputEventTimestamps TakeLastEventTimestamps() override;
+  base::TimeDelta GetFrameLatency(const webrtc::DesktopFrame& frame);
 
  private:
-  ~ScrollFrameGenerator() override;
+  ~ScrollFrameGenerator();
+  friend class base::RefCountedThreadSafe<ScrollFrameGenerator>;
 
   std::unique_ptr<webrtc::DesktopFrame> base_frame_;
   base::TimeTicks start_time_;
 
   std::unordered_map<int, base::TimeTicks> frame_timestamp_;
+
+  // Id of the last frame encoded on the barcode.
+  int last_frame_id_ = -1;
 
   DISALLOW_COPY_AND_ASSIGN(ScrollFrameGenerator);
 };