Implement style invalidation tracking

LayoutTests/http/tests/inspector/timeline-test.js

 var initialize_Timeline = function() {
 
 InspectorTest.preloadPanel("timeline");
 WebInspector.TempFile = InspectorTest.TempFileMock;
 
 // Scrub values when printing out these properties in the record or data field.
 InspectorTest.timelinePropertyFormatters = {
     children: "formatAsTypeName",
     endTime: "formatAsTypeName",
     requestId: "formatAsTypeName",
@@ skipping 16 matching lines @@
     identifier: "formatAsTypeName",
     clip: "formatAsTypeName",
     root: "formatAsTypeName",
     backendNodeId: "formatAsTypeName",
     nodeId: "formatAsTypeName",
     rootNode: "formatAsTypeName",
     networkTime: "formatAsTypeName",
     thread: "formatAsTypeName"
 };
 
+InspectorTest.InvalidationFormatters = {
+    _tracingEvent: "skip",
+    cause: "formatAsInvalidationCause",
+    frame: "skip",
+    invalidatedSelectorId: "skip",
+    invalidationList: "skip",
+    invalidationSet: "skip",
+    linkedRecalcStyleEvent: "skip",
+    linkedLayoutEvent: "skip",
+    nodeId: "skip",
+    paintId: "skip",
+    startTime: "skip",
+};
+
+InspectorTest.formatters.formatAsInvalidationCause = function(cause)
+{
+    if (!cause)
+        return "<undefined>";
+    var stackTrace;
+    if (cause.stackTrace && cause.stackTrace.length)
+        stackTrace = InspectorTest.formatters.formatAsURL(cause.stackTrace[0].url) + ":" + cause.stackTrace[0].lineNumber;
+    return "{reason: " + cause.reason + ", stackTrace: " + stackTrace + "}";
+}
+
 InspectorTest.switchTimelineToWaterfallMode = function()
 {
     if (WebInspector.panels.timeline._flameChartToggleButton.toggled())
         WebInspector.panels.timeline._flameChartToggleButton.element.click();
 }
 
 InspectorTest.timelinePresentationModel = function()
 {
     InspectorTest.switchTimelineToWaterfallMode();
     return WebInspector.panels.timeline._currentViews[0]._presentationModel;
@@ skipping 315 matching lines @@
         return this._fileSize;
     },
 
     fileName: function()
     {
         return "fakeFile";
     }
 };
 
 };