Oilpan: fix build after r199293.

Source/platform/fonts/GlyphPageTreeNodeTest.cpp

Index: Source/platform/fonts/GlyphPageTreeNodeTest.cpp
diff --git a/Source/platform/fonts/GlyphPageTreeNodeTest.cpp b/Source/platform/fonts/GlyphPageTreeNodeTest.cpp
index 66a95481cc9bf6f81617b9e47fe8be807e960d79..40f57ec369d918a6e778f58a6b1cea0b9618d3fb 100644
--- a/Source/platform/fonts/GlyphPageTreeNodeTest.cpp
+++ b/Source/platform/fonts/GlyphPageTreeNodeTest.cpp
@@ -15,7 +15,7 @@ namespace {
 
 class TestCustomFontData : public CustomFontData {
 public:
-    static PassRefPtr<TestCustomFontData> create() { return adoptRef(new TestCustomFontData()); }
+    static PassRefPtrWillBeRawPtr<TestCustomFontData> create() { return adoptRefWillBeNoop(new TestCustomFontData()); }
 private:
     TestCustomFontData() { }
     bool isLoadingFallback() const override { return true; }