Oilpan: Remove most WillBe types from the code base

third_party/WebKit/Source/modules/webgl/WebGLContextGroup.h

Index: third_party/WebKit/Source/modules/webgl/WebGLContextGroup.h
diff --git a/third_party/WebKit/Source/modules/webgl/WebGLContextGroup.h b/third_party/WebKit/Source/modules/webgl/WebGLContextGroup.h
index bf448b3811c2874bf1a6df1c646227d10a7301d4..53d261fe37e7a58f240edae10ac5a2acf9b7524a 100644
--- a/third_party/WebKit/Source/modules/webgl/WebGLContextGroup.h
+++ b/third_party/WebKit/Source/modules/webgl/WebGLContextGroup.h
@@ -70,7 +70,7 @@ private:
     // registration with WebGLContextGroup, and vice versa, the
     // WebGLContextGroup takes care of detaching the group objects if
     // the set of WebGLRenderingContextBase contexts becomes empty.
-    HashSet<RawPtrWillBeUntracedMember<WebGLRenderingContextBase>> m_contexts;
+    HashSet<UntracedMember<WebGLRenderingContextBase>> m_contexts;
     HashSet<UntracedMember<WebGLSharedObject>> m_groupObjects;
 };