Not sure if this is still needed. Sending it to Martijn for opinion.
The idea was to have the infobar the same color as the other "almost white" elements (NTP, popup menu...), 98% white.

This is related to question #6 in  issue 843571 

This is still needed. Originally I had suggested making the toolbar have knowledge of the infobar and thus changing the height of the toolbar to accommodate a [transparent background] infobar. This obviously is a bad idea and doesn't scale, so I suggest we just use the same kind of visual effect background view as that used in the toolbar, place a "separator" line along the bottom edge of the infobar view (say a 1pt high rect that spans the width of the infobar with a background color of white inside the vibrancy content view). We can then sprinkle in some logic to show/hide the separator view in certain size classes (Any x Compact or Regular x Any) and maybe also when we are in fullscreen for Compact x Regular (not sure if there is a global notification posted for fullscreen that we can use ... if no it isn't worth coupling the two areas of code).

I imagine it looking like this (shown with a colorful background to illustrate the subtle transparency).

Deleted: Screen Shot 2018-05-18 at 13.48.01.png 175 KB

	Screen Shot 2018-05-18 at 13.48.01.png 175 KB View Download

This has more to do with infobar than toolbar, so taking it back.

 Issue 848876  has been merged into this issue.

Use #fafafa, no blur.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/aefab4ccb6631af2895726d8e2487e3419b7bea7

commit aefab4ccb6631af2895726d8e2487e3419b7bea7
Author: Gauthier Ambard <gambard@chromium.org>
Date: Tue Jul 03 06:49:37 2018

[iOS] Change the background color of the infobars

This CL changes the background color of the infobars to be more aligned
with the UI Refresh look.

Bug:  817753 
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I06db3d63b619fc63bf381d936f4c59cab4afaa28
Reviewed-on: https://chromium-review.googlesource.com/1122860
Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Reviewed-by: Peter Lee <pkl@chromium.org>
Commit-Queue: Gauthier Ambard <gambard@chromium.org>
Cr-Commit-Position: refs/heads/master@{#572129}
[modify] https://crrev.com/aefab4ccb6631af2895726d8e2487e3419b7bea7/ios/chrome/browser/ui/autofill/save_card_infobar_view.mm
[modify] https://crrev.com/aefab4ccb6631af2895726d8e2487e3419b7bea7/ios/chrome/browser/ui/infobars/BUILD.gn
[modify] https://crrev.com/aefab4ccb6631af2895726d8e2487e3419b7bea7/ios/chrome/browser/ui/infobars/confirm_infobar_view.mm
[add] https://crrev.com/aefab4ccb6631af2895726d8e2487e3419b7bea7/ios/chrome/browser/ui/infobars/infobar_constants.h
[add] https://crrev.com/aefab4ccb6631af2895726d8e2487e3419b7bea7/ios/chrome/browser/ui/infobars/infobar_constants.mm

Tested on 69.0.3487.0 Canary, iPhone X  iOS 11.4, it looks different than the image in comment #6, is this WAI?
https://drive.google.com/file/d/1RYe0uyxm8NUJbph6qL0fbTCVbf2nvbMP/view

Yes, if you look at comment #11, we decided to just change the color to FAFAFA and not extending the blur.

Verified on 69.0.3487.0 Canary, iPhone X  iOS 11.4,
Looks good.

Correct verification Image:
https://drive.google.com/file/d/1rZjwhuqs-U5cx90jdrEoVVtcs9ybbwQW/view