Prereqs if recording from Android:
Zip the file if you can. It'll compress a 40MB file to about 4MB.Now you can share it: attaching it to a bug, emailing it, or sharing via dropbox/etc.
- Inspect the tab w/ devtools, open Timeline panel.
- The only checkbox checked should be JS Profile.
- Hit record.
- Do whatever action is slow. (reload, tapping an icon, scrolling).
- End the recording
- If that looks like it captured the right stuff, right-click and save it.