The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6e0bc1c5d7f0b2b14430523a4189939243c7f53e

commit 6e0bc1c5d7f0b2b14430523a4189939243c7f53e
Author: Varun Khaneja <vakh@chromium.org>
Date: Sat Sep 09 01:55:24 2017

Change the update timeout to 15 mins to prevent timeouts on slow connections

Bug:  763589 
Change-Id: I1d8a25701b5136f5b757e9093eb8253f9792bf9d
Reviewed-on: https://chromium-review.googlesource.com/658559
Commit-Queue: Nathan Parker <nparker@chromium.org>
Reviewed-by: Nathan Parker <nparker@chromium.org>
Cr-Commit-Position: refs/heads/master@{#500778}
[modify] https://crrev.com/6e0bc1c5d7f0b2b14430523a4189939243c7f53e/components/safe_browsing_db/v4_update_protocol_manager.cc

This landed in 63.0.3212.0. I'm still waiting for the UMA to show that it reduced the time outs. http://shortn/_znsoih4NmC

This seems to have done the expected i.e. drop the number of timeouts to an all-time low. See shortn link above.

Requesting merge approval for this trivial change because without this change, desktop users on very slow networks are unable to use Safe Browsing protection.

Diff is just this:
-static const int kV4TimerUpdateWaitSecMax = 30;
+static const int kV4TimerUpdateWaitSecMax = 15 * 60;  // 15 minutes

i.e change timeout interval from 30 seconds to 15 minutes.

This bug requires manual review: M62 has already been promoted to the beta branch, so this requires manual review
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), bhthompson@(ChromeOS), abdulsyed@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Thanks for the fix - approving merge to M62 (branch: 3202). 

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/853e16f977dcbf97875f9c41532fde5a6f3c9b87

commit 853e16f977dcbf97875f9c41532fde5a6f3c9b87
Author: Varun Khaneja <vakh@chromium.org>
Date: Thu Sep 14 20:58:53 2017

[62] Change update timeout to 15min to reduce timeouts on slow networks

TBR=vakh@chromium.org

(cherry picked from commit 6e0bc1c5d7f0b2b14430523a4189939243c7f53e)

Bug:  763589 
Change-Id: I1d8a25701b5136f5b757e9093eb8253f9792bf9d
Reviewed-on: https://chromium-review.googlesource.com/658559
Commit-Queue: Nathan Parker <nparker@chromium.org>
Reviewed-by: Nathan Parker <nparker@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#500778}
Reviewed-on: https://chromium-review.googlesource.com/667959
Reviewed-by: Varun Khaneja <vakh@chromium.org>
Cr-Commit-Position: refs/branch-heads/3202@{#231}
Cr-Branched-From: fa6a5d87adff761bc16afc5498c3f5944c1daa68-refs/heads/master@{#499098}
[modify] https://crrev.com/853e16f977dcbf97875f9c41532fde5a6f3c9b87/components/safe_browsing_db/v4_update_protocol_manager.cc

This change went into Beta today. I'm tracking the metrics for all channels here: http://shortn/_m8N5qhQrBo

Went into M62 at: 62.0.3202.24
Current Beta: 62.0.3202.29

+francois FYI, though it may not apply to Firefox since it is a Chrome implementation bug.