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 0b905f9a7de1aa1979980029b5f49d369558d4f8..8c25729a8bc850f2430012ae84c6c13e2d0cce6c 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"
@@ -738,7 +739,18 @@ 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