[CSSGridLayout] Switch from parentheses to brackets for grid line names

LayoutTests/fast/css-grid-layout/resources/grid-columns-rows-get-set-multiple.js

 description('Test that setting and getting grid-template-columns and grid-template-rows works as expected');
 
 debug("Test getting |grid-template-columns| and |grid-template-rows| set through CSS");
 testGridDefinitionsValues(document.getElementById("gridWithFixedElement"), "7px 11px", "17px 2px");
 testGridDefinitionsValues(document.getElementById("gridWithPercentElement"), "424px 792px", "162px 312px");
 testGridDefinitionsValues(document.getElementById("gridWithPercentWithoutSize"), "7px 0px", "11px 0px");
 testGridDefinitionsValues(document.getElementById("gridWithAutoElement"), "0px 17px", "0px 3px");
 testGridDefinitionsValues(document.getElementById("gridWithEMElement"), "100px 120px", "150px 170px");
 testGridDefinitionsValues(document.getElementById("gridWithThreeItems"), "15px 0px 100px", "120px 18px 0px");
 testGridDefinitionsValues(document.getElementById("gridWithPercentAndViewportPercent"), "400px 120px", "210px 168px");
@@ skipping 55 matching lines @@
 testGridDefinitionsSetBadJSValues("minmax(min-content, calc() 250px", "calc(2em(");
 
 function testInherit()
 {
     var parentElement = document.createElement("div");
     document.body.appendChild(parentElement);
     parentElement.style.display = "grid";
     parentElement.style.width = "800px";
     parentElement.style.height = "600px";
     parentElement.style.font = "10px Ahem"; // Used to resolve em font consistently.
-    parentElement.style.gridTemplateColumns = "50px 1fr (last)";
-    parentElement.style.gridTemplateRows = "2em (middle) 45px";
-    testGridDefinitionsValues(parentElement, "50px 750px (last)", "20px (middle) 45px");
+    parentElement.style.gridTemplateColumns = "50px 1fr [last]";
+    parentElement.style.gridTemplateRows = "2em [middle] 45px";
+    testGridDefinitionsValues(parentElement, "50px 750px [last]", "20px [middle] 45px");
 
     element = document.createElement("div");
     parentElement.appendChild(element);
     element.style.display = "grid";
     element.style.gridTemplateColumns = "inherit";
     element.style.gridTemplateRows = "inherit";
-    testGridDefinitionsValues(element, "50px 0px (last)", "20px (middle) 45px");
+    testGridDefinitionsValues(element, "50px 0px [last]", "20px [middle] 45px");
 
     document.body.removeChild(parentElement);
 }
 debug("");
 debug("Test setting grid-template-columns and grid-template-rows to 'inherit' through JS");
 testInherit();
 
 function testInitial()
 {
     element = document.createElement("div");
     document.body.appendChild(element);
     element.style.display = "grid";
     element.style.width = "800px";
     element.style.height = "600px";
-    element.style.gridTemplateColumns = "150% (middle) 55px";
-    element.style.gridTemplateRows = "1fr (line) 2fr (line)";
-    testGridDefinitionsValues(element, "1200px (middle) 55px", "200px (line) 400px (line)");
+    element.style.gridTemplateColumns = "150% [middle] 55px";
+    element.style.gridTemplateRows = "1fr [line] 2fr [line]";
+    testGridDefinitionsValues(element, "1200px [middle] 55px", "200px [line] 400px [line]");
 
     element.style.gridTemplateColumns = "initial";
     element.style.gridTemplateRows = "initial";
     shouldBe("getComputedStyle(element, '').getPropertyValue('grid-template-columns')", "'none'");
     shouldBe("getComputedStyle(element, '').getPropertyValue('grid-template-rows')", "'none'");
 
     document.body.removeChild(element);
 }
 debug("");
 debug("Test setting grid-template-columns and grid-template-rows to 'initial' through JS");
 testInitial();