Revert of Use system timestamp as capture timestamp

media/capture/video/mac/video_capture_device_mac.mm

Index: media/capture/video/mac/video_capture_device_mac.mm
diff --git a/media/capture/video/mac/video_capture_device_mac.mm b/media/capture/video/mac/video_capture_device_mac.mm
index 432fbfbf4343231e42d82878bbd0dc5ec5886c69..ec6fcaf83f9279d46beea362f6b16a9814607456 100644
--- a/media/capture/video/mac/video_capture_device_mac.mm
+++ b/media/capture/video/mac/video_capture_device_mac.mm
@@ -545,8 +545,18 @@
     return;
   }
 
+  base::TimeTicks aligned_timestamp;
+  if (timestamp == media::kNoTimestamp()) {
+    aligned_timestamp = base::TimeTicks::Now();
+  } else {
+    if (first_timestamp_ == media::kNoTimestamp()) {
+      first_timestamp_ = timestamp;
+      first_aligned_timestamp_ = base::TimeTicks::Now();
+    }
+    aligned_timestamp = first_aligned_timestamp_ + timestamp - first_timestamp_;
+  }
   client_->OnIncomingCapturedData(video_frame, video_frame_length, frame_format,
-                                  0, base::TimeTicks::Now());
+                                  0, aligned_timestamp);
 }
 
 void VideoCaptureDeviceMac::ReceiveError(