Set objects to need full paint invalidation after clearing their invalidation rects.

third_party/WebKit/Source/core/testing/Internals.h

Index: third_party/WebKit/Source/core/testing/Internals.h
diff --git a/third_party/WebKit/Source/core/testing/Internals.h b/third_party/WebKit/Source/core/testing/Internals.h
index 674cd8d6576817414eca453f31f4e756ecff62d2..9ada88e8d88b982745452a86b6cd07ae08584847 100644
--- a/third_party/WebKit/Source/core/testing/Internals.h
+++ b/third_party/WebKit/Source/core/testing/Internals.h
@@ -400,6 +400,9 @@ public:
     // or -1 if the node does not have a scrollable area.
     String getProgrammaticScrollAnimationState(Node*) const;
 
+    // Returns the visual rect of a node's LayoutObject.
+    ClientRect* visualRect(Node*);
+
 private:
     explicit Internals(ScriptState*);
     Document* contextDocument() const;