Chrome Version: 71.3578.99, 72.0.3626.53
OS: Android Pi

What steps will reproduce the problem?
(1) Go to chrome:flags via the omnibox.
(2) Activate TalkBack (settings > accessibility > TalkBack or hold volume keys for three seconds and select TalkBack from the dialog that appears)
(3) Scroll the screen by swiping up or down with two fingers, then swipe up or down with one finger.
(4) Swipe down with one finger until TalkBack says "controls" then swipe left or right.

What is the expected result?
TalkBack should respond in a timely manner.

What happens instead?
TalkBack performance is extremely poor in web pages with several 		elements. Specifically:
-It takes Talkback anywhere from 5 to 10 seconds to become fully responsive after a page is scrolled with two fingers. I tested this by changing granularity (swipe up or down with one finger) and waiting for TalkBack to speak the change.
-If a user moves by controls on this page, TalkBack will take a two to three second nap before it says the name of each control. If a user wants to swipe past multiple controls it will take around five to seven seconds for TalkBack to react to the input.
Additional notes:
Tested with a Pixel 1 and OP5, the better numbers were from the Pixel, which surprises me.
it does not appear that focus is explicitly set by the scroll event. TalkBack is silent after a scroll and if the user swipes right on default granularity, focus returns to the initially focused item. The screen must be explored before focus jumps to the right place.
Performance on dev is similar, however focus often disappears entirely on Chrome 73 after a scroll.