Use refs for non-null GraphicsContext, Scrollbar, etc. in scrollbar related code

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

Index: third_party/WebKit/Source/core/testing/Internals.cpp
diff --git a/third_party/WebKit/Source/core/testing/Internals.cpp b/third_party/WebKit/Source/core/testing/Internals.cpp
index ef4671f7d9f7abd770693102274cd2f66a78308b..511576e7591a42685a865b6e64b8f26a6a357f05 100644
--- a/third_party/WebKit/Source/core/testing/Internals.cpp
+++ b/third_party/WebKit/Source/core/testing/Internals.cpp
@@ -2517,11 +2517,7 @@ bool Internals::setScrollbarVisibilityInScrollableArea(Node* node, bool visible)
     ScrollableArea* scrollableArea = layer->scrollableArea();
     if (!scrollableArea)
         return false;
-    ScrollAnimatorBase* animator = layer->scrollableArea()->scrollAnimator();
-    if (!animator)
-        return false;
-
-    return animator->setScrollbarsVisibleForTesting(visible);
+    return layer->scrollableArea()->scrollAnimator().setScrollbarsVisibleForTesting(visible);
 }
 
 void Internals::forceRestrictIFramePermissions()