DevTools: defer styles delta calculation to until the end of the task.

LayoutTests/inspector/elements/styles/dynamic-style-tag.html

Index: LayoutTests/inspector/elements/styles/dynamic-style-tag.html
diff --git a/LayoutTests/inspector/elements/styles/dynamic-style-tag.html b/LayoutTests/inspector/elements/styles/dynamic-style-tag.html
index e893ea052177c6d34faf734b893db2d738476d95..0b858edbfb50dda93b47f1f604b7358379410e14 100644
--- a/LayoutTests/inspector/elements/styles/dynamic-style-tag.html
+++ b/LayoutTests/inspector/elements/styles/dynamic-style-tag.html
@@ -30,6 +30,7 @@ var test = function()
 {
     WebInspector.cssModel.addEventListener(WebInspector.CSSStyleModel.Events.StyleSheetAdded, styleSheetAdded);
     InspectorTest.reloadPage(step1);
+    var styleSheets = [];
 
     function pathToFileName(path)
     {
@@ -40,30 +41,30 @@ var test = function()
     {
         InspectorTest.selectNodeAndWaitForStyles("inspected", step2);
     }
-    
+
     function step2()
     {
+        styleSheets.sort();
+        for (var i = 0; i < styleSheets.length; ++i)
+            InspectorTest.addResult(styleSheets[i]);
         InspectorTest.dumpSelectedElementStyles(true, false, true);
         InspectorTest.completeTest();
     }
     
-    function dumpStyleSheetHeader(header, text)
-    {
-        InspectorTest.addResult("Stylesheet added:");
-        InspectorTest.addResult("  - isInline: " + header.isInline);
-        InspectorTest.addResult("  - sourceURL: " + pathToFileName(header.sourceURL));
-        InspectorTest.addResult("  - hasSourceURL: " + header.hasSourceURL);
-        InspectorTest.addResult("  - contents: " + text);
-    }
-    
     function styleSheetAdded(event)
     {
         var header = event.data;
+        var text = ["Stylesheet added:"];
+        text.push("  - isInline: " + header.isInline);
+        text.push("  - sourceURL: " + pathToFileName(header.sourceURL));
+        text.push("  - hasSourceURL: " + header.hasSourceURL);
+
         CSSAgent.getStyleSheetText(header.id, contentLoaded.bind(this));
 
-        function contentLoaded(error, text)
+        function contentLoaded(error, content)
         {
-            dumpStyleSheetHeader(header, text);
+            text.push("  - contents: " + content);
+            styleSheets.push(text.join("\n"));
         }
     }
 }