Simplify incremental paint invalidation

third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp

Index: third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
index 7fe49b034efb7cb49ab24f0cac61828e7ef8ba14..83bbc97bc429ef36fed16c0bf2f5e5c81be29e20 100644
--- a/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
+++ b/third_party/WebKit/Source/platform/graphics/GraphicsLayer.cpp
@@ -517,13 +517,16 @@ void GraphicsLayer::resetTrackedRasterInvalidations() {
 }
 
 bool GraphicsLayer::hasTrackedRasterInvalidations() const {
-  RasterInvalidationTracking* tracking =
-      rasterInvalidationTrackingMap().find(this);
-  if (tracking)
+  if (auto* tracking = getRasterInvalidationTracking())
     return !tracking->trackedRasterInvalidations.isEmpty();
   return false;
 }
 
+const RasterInvalidationTracking* GraphicsLayer::getRasterInvalidationTracking()
+    const {
+  return rasterInvalidationTrackingMap().find(this);
+}
+
 void GraphicsLayer::trackRasterInvalidation(const DisplayItemClient& client,
                                             const IntRect& rect,
                                             PaintInvalidationReason reason) {