[Devtools] Cleanup DataGrid's typecast and identifier naming

third_party/WebKit/LayoutTests/inspector/profiler/heap-snapshot-summary-sorting-fields.html

Index: third_party/WebKit/LayoutTests/inspector/profiler/heap-snapshot-summary-sorting-fields.html
diff --git a/third_party/WebKit/LayoutTests/inspector/profiler/heap-snapshot-summary-sorting-fields.html b/third_party/WebKit/LayoutTests/inspector/profiler/heap-snapshot-summary-sorting-fields.html
index e9825c2242f16bb9c9754783bb9d24a57465573e..36910cf1cbb111ad23301aaba1af664fb799dc81 100644
--- a/third_party/WebKit/LayoutTests/inspector/profiler/heap-snapshot-summary-sorting-fields.html
+++ b/third_party/WebKit/LayoutTests/inspector/profiler/heap-snapshot-summary-sorting-fields.html
@@ -62,12 +62,12 @@ function test()
             function step4(newColumnState)
             {
                 columns[currentColumn] = newColumnState;
-                var columnName = columns[currentColumn].identifier;
+                var columnName = columns[currentColumn].id;
                 var contents = windowRow.children.map(function(obj) { return obj.element().children[currentColumn].textContent; });
                 InspectorTest.assertEquals(instanceCount, contents.length, "column contents");
                 var sortTypes = { object: "text", distance: "number", count: "number", shallowSize: "size", retainedSize: "size" };
-                InspectorTest.assertEquals(true, !!sortTypes[columns[currentColumn].identifier], "sort by identifier");
-                InspectorTest.checkArrayIsSorted(contents, sortTypes[columns[currentColumn].identifier], columns[currentColumn].sort);
+                InspectorTest.assertEquals(true, !!sortTypes[columns[currentColumn].id], "sort by id");
+                InspectorTest.checkArrayIsSorted(contents, sortTypes[columns[currentColumn].id], columns[currentColumn].sort);
 
                 if (!currentColumnOrder)
                     currentColumnOrder = true;