Bug 197067

The following list of shorthand properties all exhibit the same error in that values stored in CSSStyleDeclaration object are invalid. - grid - grid-area - grid-column - grid-row - grid-template Simple example for grid-area property: ``` const style = document.createElement('style'); document.head.appendChild(style); style.sheet.insertRule('.surprise { grid-area: 1 / 2 / 3 / 4; }'); console.log(style.sheet.cssRules[0].style.gridArea); ``` expected: ``` > "1 / 2 / 3 / 4" ``` actual: ``` > "1 2 3 4" ``` The same type of issue occurs for each of the css grid shorthand properties. Seems possibly related to the char '/' but could be a bad signal too.