Refactor to centralize code which decides whether ObjectPaintProperties are needed.

third_party/WebKit/Source/core/paint/RarePaintData.cpp

Index: third_party/WebKit/Source/core/paint/RarePaintData.cpp
diff --git a/third_party/WebKit/Source/core/paint/RarePaintData.cpp b/third_party/WebKit/Source/core/paint/RarePaintData.cpp
index 0a2ec1f22cb621c7e92f244cb48100a9c9d65e65..896be5123214fb527973d4f34edf7484b5f6e782 100644
--- a/third_party/WebKit/Source/core/paint/RarePaintData.cpp
+++ b/third_party/WebKit/Source/core/paint/RarePaintData.cpp
@@ -23,6 +23,10 @@ ObjectPaintProperties& RarePaintData::EnsurePaintProperties() {
   return *paint_properties_.get();
 }
 
+void RarePaintData::ClearPaintProperties() {
+  paint_properties_.reset(nullptr);
+}
+
 void RarePaintData::ClearLocalBorderBoxProperties() {
   local_border_box_properties_ = nullptr;
 }