Let FrameView track object paint invalidations

third_party/WebKit/Source/core/frame/LocalFrame.cpp

Index: third_party/WebKit/Source/core/frame/LocalFrame.cpp
diff --git a/third_party/WebKit/Source/core/frame/LocalFrame.cpp b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
index 68ff6e0e920b56189424e7e442f1b099973e9f43..c560ef942a27f947000ff5996ca4294ae33c31c0 100644
--- a/third_party/WebKit/Source/core/frame/LocalFrame.cpp
+++ b/third_party/WebKit/Source/core/frame/LocalFrame.cpp
@@ -69,6 +69,7 @@
 #include "core/paint/TransformRecorder.h"
 #include "core/svg/SVGDocumentExtensions.h"
 #include "platform/DragImage.h"
+#include "platform/JSONValues.h"
 #include "platform/PluginScriptForbiddenScope.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/ScriptForbiddenScope.h"
@@ -735,7 +736,18 @@ String LocalFrame::layerTreeAsText(unsigned flags) const
     if (contentLayoutItem().isNull())
         return String();
 
-    return contentLayoutItem().compositor()->layerTreeAsText(static_cast<LayerTreeFlags>(flags));
+    RefPtr<JSONObject> layerTree = contentLayoutItem().compositor()->layerTreeAsJSON(static_cast<LayerTreeFlags>(flags));
+
+    if (flags & LayerTreeIncludesPaintInvalidations) {
+        RefPtr<JSONArray> objectPaintInvalidations = m_view->trackedObjectPaintInvalidationsAsJSON();
+        if (objectPaintInvalidations) {
+            if (!layerTree)
+                layerTree = JSONObject::create();
+            layerTree->setArray("objectPaintInvalidations", objectPaintInvalidations);
+        }
+    }
+
+    return layerTree ? layerTree->toPrettyJSONString() : String();
 }
 
 bool LocalFrame::shouldThrottleRendering() const