More info here:
- add grey background to each tile (grey = Google100 6%)
- set transition-duration for each tile to mitigate effect of slow loading tile data (similar to  issue 859373 ).

I think that requests for all images in the grid are issued at the same time, so some that won't be visible until the user scrolls are available before the first N that are visible.

The tile image sizes are pretty small now (issue 851990), so perhaps it won't make a difference except on very slow networks, but it might be worth requesting the images for tiles that are visible first. Just a hunch - we'd have to try it out to see if it makes any discernible difference.

Assigning to Weilun but please ask Kyle for advice if needed

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/4387ccdbb9d366c9480fcfa8827b8aa5691c96f7

commit 4387ccdbb9d366c9480fcfa8827b8aa5691c96f7
Author: Weilun Shi <sweilun@chromium.org>
Date: Wed Aug 22 18:09:10 2018

[NTP] Add background image selection transition effect

Every tile in the custom background dialog are now have the same fade in
effect as when custom background is loaded.

Bug:  870401 
Change-Id: I744a891b7afccf0e0ee76526316f13e2181593dd
Reviewed-on: https://chromium-review.googlesource.com/1182450
Reviewed-by: Kristi Park <kristipark@chromium.org>
Commit-Queue: Weilun Shi <sweilun@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585166}
[modify] https://crrev.com/4387ccdbb9d366c9480fcfa8827b8aa5691c96f7/chrome/browser/resources/local_ntp/custom_backgrounds.css
[modify] https://crrev.com/4387ccdbb9d366c9480fcfa8827b8aa5691c96f7/chrome/browser/resources/local_ntp/custom_backgrounds.js

Moving comment #3 to a new bug:  issue 876814 .

yyushkina@ As per comment #0 could you please provide the proper/specific steps to reproduce the issue from TE-End. If possible provide screenshot. Hence adding Needs-Feedback label to it.

Thanks...!

Weilun: can you provide some repro info here, per comment #12? I think a screencast might help. Thanks!

Sorry for the late reply. Kindly refer to the screencast for reference.

When we change default(white) background to custom background, there is a transition effect. This CL is to add the same transition effect when we open the custom background dialog. You can see the effect more obvious on a slow network. Thanks! 

Deleted: capture.webm 18.6 MB

capture.webm 18.6 MB Download