DevTools: require enabling CSS domain before running CSS.* commands.

third_party/WebKit/LayoutTests/inspector-protocol/css/css-get-platform-fonts.html

Index: third_party/WebKit/LayoutTests/inspector-protocol/css/css-get-platform-fonts.html
diff --git a/third_party/WebKit/LayoutTests/inspector-protocol/css/css-get-platform-fonts.html b/third_party/WebKit/LayoutTests/inspector-protocol/css/css-get-platform-fonts.html
index 616c59419ca39a96d2793fa20c032603fca34065..bc8d88007d779c6397fd27fe80b8eb7f4fa50cf8 100644
--- a/third_party/WebKit/LayoutTests/inspector-protocol/css/css-get-platform-fonts.html
+++ b/third_party/WebKit/LayoutTests/inspector-protocol/css/css-get-platform-fonts.html
@@ -28,20 +28,13 @@ function test()
     }
 
 
-    function platformFontsForElementWithSelector(selector, callback)
+    async function platformFontsForElementWithSelector(selector, callback)
     {
-        InspectorTest.requestNodeId(documentNodeId, selector, onNodeId);
-
-        function onNodeId(nodeId)
-        {
-            InspectorTest.sendCommandOrDie("CSS.getPlatformFontsForNode", { nodeId: nodeId }, onGotComputedFonts);
-        }
-
-        function onGotComputedFonts(response)
-        {
-            dumpComputedFonts(response);
-            callback();
-        }
+        var nodeId = await InspectorTest.requestNodeId(documentNodeId, selector);
+        await InspectorTest.sendCommandOrDie("CSS.enable", {  });
+        var response = await InspectorTest.sendCommandOrDie("CSS.getPlatformFontsForNode", { nodeId: nodeId });
+        dumpComputedFonts(response);
+        callback();
     }
 
     function dumpComputedFonts(response)