_This is not a bug report, but rather an enhancement request_
Title may be confusing, as I was finding a hard time to describe this issue in a few words to write the title. But I will explain this further. To provide context, when I say "theme", or name of a theme, I am refering to the theme within Google Chrome (unless I specifically say otherwise)
Google Chrome, I don't recall from which version, introduced a better integration with the GTK environment by allowing a more integrated look with the host's DE and theme. Here is an article that describes the feature when it is still in developmental phase.
The changes work well really, for all themes that I have tried as far as I am concerned, including Flat Plat back then. I always wanted to use the default GTK theme as the colour scheme is still acceptable for me (it is slightly grey), but there is something bothering me: __The toolbar is missing a bottom border if I use the stock Chrome's GTK theme while the DE is using Materia.__ I have been using the Materia crx theme for so long now in patience, but I still crave to use the stock GTK theme from time to time. Especially for the look of window buttons, plus the ease of closing the chrome window by just sliding the cursor to the top right of the screen. Figured out I should drop a request, because for other themes, there are no problems at all.
To use GTK theme, open Settings, under category "Appearance" of the section "Theme", click on "Use GTK+"
Below are screenshots showing the missing bottom border for Chrome GTK theme. The bottom border is in fact visible for Classic and Materia.
__Chrome GTK__

(Notice the slight grey compared to Materia below. I am fine with that, and it is not the point of this issue :v:)
__Materia__

__Chrome Classic__

__Chrome GTK Maximised__

__Chrome GTK (Adwaita on DE)__

I have also included the look of it if I used Adwaita on my Gnome desktop, and the bottom border is present. Since Materia is based on Adwaita, I hope maybe something could aid in implementing the border in Materia
As always, feature requests are just "requests" and it is up to the developer to add it or not! 馃槃
If you report a bug or ask a question, please include the following information as required:
pkg-config --modversion gtk+-3.0)Hey, thanks for the detailed report ;) I've addressed this issue finally.
However, Chrome's GTK+ theme integration is still not very good, so I'd still recommend using Chrome theme and enabling "Use system title bar and borders" so far...
One word: You are awesome! 馃榿
I'm always using "Use system title bar and borders" even if Chrome did manage to draw the pixels using correct colors because it doesn't seem to pick up the behavior of the window manager. For example, I have my window title bars to open context menu with right button that has options to move the window to another desktop, force "Always on top" and clicking window title bar with middle mouse button will toggle maximize vertically. I often use every one of those options and non-system title bar misses every one of those.
Most helpful comment
Hey, thanks for the detailed report ;) I've addressed this issue finally.
However, Chrome's GTK+ theme integration is still not very good, so I'd still recommend using Chrome theme and enabling "Use system title bar and borders" so far...