This patch will apply the grid layout to the toolbar.
If devtools's width is narrow, we expected that devtool display chevron and the
controls elements only(i.e. chevron and meatball and close button).
In order to display these button, a wrapper of toolbar will use grid layout.
Basically, this patch define grid columns as follow:
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| Picker | tooltabs | commands | controls |
| auto | 26px ~ 1fr | auto | max-content|
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We can disable the picker and command buttons, in this case, a toolbar will
stretch the tooltabs width by using grid-column-start/end.
MozReview-Commit-ID: ByY2qt2xhAg
Mantaroh Yoshinaga
789d970ebe