Oilpan: Remove most WillBe types from the code base

third_party/WebKit/Source/core/animation/AnimationTimelineTest.cpp

Index: third_party/WebKit/Source/core/animation/AnimationTimelineTest.cpp
diff --git a/third_party/WebKit/Source/core/animation/AnimationTimelineTest.cpp b/third_party/WebKit/Source/core/animation/AnimationTimelineTest.cpp
index 17f4054681e2cbd9f035e7aad52fad1a5d354e53..b8b38fb953d4133ac340ef88e8d4af728b9f13dc 100644
--- a/third_party/WebKit/Source/core/animation/AnimationTimelineTest.cpp
+++ b/third_party/WebKit/Source/core/animation/AnimationTimelineTest.cpp
@@ -89,8 +89,8 @@ protected:
     }
 
     OwnPtr<DummyPageHolder> pageHolder;
-    RefPtrWillBePersistent<Document> document;
-    RefPtrWillBePersistent<Element> element;
+    Persistent<Document> document;
+    Persistent<Element> element;
     Persistent<AnimationTimeline> timeline;
     Timing timing;
     Persistent<MockPlatformTiming> platformTiming;