[CSS Grid Layout] Update named grid lines syntax to the last version of the specs

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

 description('Test that setting and getting grid-definition-columns and grid-definition-rows works as expected');
 
 debug("Test getting |grid-definition-columns| and |grid-definition-rows| set through CSS");
 testGridDefinitionsValues(document.getElementById("gridWithFixedElement"), "7px 11px", "17px 2px");
 testGridDefinitionsValues(document.getElementById("gridWithPercentElement"), "53% 99%", "27% 52%", "424px 792px", "162px 312px");
 testGridDefinitionsValues(document.getElementById("gridWithAutoElement"), "auto auto", "auto auto", "0px 17px", "0px 3px");
 testGridDefinitionsValues(document.getElementById("gridWithEMElement"), "100px 120px", "150px 170px");
 testGridDefinitionsValues(document.getElementById("gridWithThreeItems"), "15px auto 100px", "120px 18px auto", "15px 0px 100px", "120px 18px 0px");
 testGridDefinitionsValues(document.getElementById("gridWithPercentAndViewportPercent"), "50% 120px", "35% 168px", "400px 120px", "210px 168px");
 testGridDefinitionsValues(document.getElementById("gridWithFitContentAndFitAvailable"), "none", "none");
@@ skipping 45 matching lines @@
 testGridDefinitionsSetBadJSValues("10px minmax(16px, -1vw)", "minmax(-1%, 15%) 10vw");
 
 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.gridDefinitionColumns = "50px 1fr 'last'";
-    parentElement.style.gridDefinitionRows = "2em 'middle' 45px";
-    testGridDefinitionsValues(parentElement, "50px 750px last", "20px middle 45px");
+    parentElement.style.gridDefinitionColumns = "50px 1fr (last)";
+    parentElement.style.gridDefinitionRows = "2em (middle) 45px";
+    testGridDefinitionsValues(parentElement, "50px 750px (last)", "20px (middle) 45px");
 
     element = document.createElement("div");
     parentElement.appendChild(element);
     element.style.display = "grid";
     element.style.gridDefinitionColumns = "inherit";
     element.style.gridDefinitionRows = "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-definition-columns and grid-definition-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.gridDefinitionColumns = "150% 'middle' 55px";
-    element.style.gridDefinitionRows = "1fr 'line' 2fr 'line'";
-    testGridDefinitionsValues(element, "1200px middle 55px", "200px line 400px line");
+    element.style.gridDefinitionColumns = "150% (middle) 55px";
+    element.style.gridDefinitionRows = "1fr (line) 2fr (line)";
+    testGridDefinitionsValues(element, "1200px (middle) 55px", "200px (line) 400px (line)");
 
     element.style.gridDefinitionColumns = "initial";
     element.style.gridDefinitionRows = "initial";
     shouldBe("getComputedStyle(element, '').getPropertyValue('grid-definition-columns')", "'none'");
     shouldBe("getComputedStyle(element, '').getPropertyValue('grid-definition-rows')", "'none'");
 
     document.body.removeChild(element);
 }
 debug("");
 debug("Test setting grid-definition-columns and grid-definition-rows to 'initial' through JS");
 testInitial();