Implement style invalidation tracking

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

Index: LayoutTests/http/tests/inspector/timeline-test.js
diff --git a/LayoutTests/http/tests/inspector/timeline-test.js b/LayoutTests/http/tests/inspector/timeline-test.js
index 514a8639e081a3677c1926a196e5d3769440bf80..3e893afd21a5cd45b66a081b60a9f764b5273e19 100644
--- a/LayoutTests/http/tests/inspector/timeline-test.js
+++ b/LayoutTests/http/tests/inspector/timeline-test.js
@@ -34,6 +34,30 @@ InspectorTest.timelinePropertyFormatters = {
     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())