Clean up code should be in M62. Removal should be at least M64 or maybe later.

do you remember this? is there any work remaining?

I think it's to revert the commit from the blocked on bug:
eb8ba65e8150c82259ec8c07b37db279011a06b8

Looks like the code's still there. Here's a CL:
https://chromium-review.googlesource.com/c/chromium/src/+/1364019

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/7f85b75a6d0ca2431e811c9d245765ea60773263

commit 7f85b75a6d0ca2431e811c9d245765ea60773263
Author: agrieve <agrieve@chromium.org>
Date: Thu Dec 06 18:01:50 2018

android_webview: Remove extracted pak file cleanup logic

This removes some cleanup that now has very low odds of being
necessary. It was to clean up accidentally extracted files
for users of M60 and M61 Monochrome (15 months ago).

Bug:  756580 
Change-Id: I502d7080ec26d0301a9e17e07ae9f5b7266ac088
Reviewed-on: https://chromium-review.googlesource.com/c/1364019
Reviewed-by: Richard Coles <torne@chromium.org>
Commit-Queue: agrieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#614414}
[modify] https://crrev.com/7f85b75a6d0ca2431e811c9d245765ea60773263/android_webview/java/src/org/chromium/android_webview/AwBrowserProcess.java