Oilpan: Remove most WillBe types from the code base

third_party/WebKit/Source/core/dom/MessagePort.h

Index: third_party/WebKit/Source/core/dom/MessagePort.h
diff --git a/third_party/WebKit/Source/core/dom/MessagePort.h b/third_party/WebKit/Source/core/dom/MessagePort.h
index 3117aa734a1c30a9b213ce052ffdba95873b2638..8f4332919e8bbf1230ae36b6836292eecefb55be 100644
--- a/third_party/WebKit/Source/core/dom/MessagePort.h
+++ b/third_party/WebKit/Source/core/dom/MessagePort.h
@@ -63,7 +63,7 @@ class CORE_EXPORT MessagePort
     , public WebMessagePortChannelClient {
     DEFINE_WRAPPERTYPEINFO();
     REFCOUNTED_GARBAGE_COLLECTED_EVENT_TARGET(MessagePort);
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(MessagePort);
+    USING_GARBAGE_COLLECTED_MIXIN(MessagePort);
 public:
     static MessagePort* create(ExecutionContext&);
     ~MessagePort() override;
@@ -100,7 +100,7 @@ public:
     // ActiveDOMObject implementation.
     void stop() override { close(); }
 
-    void setOnmessage(PassRefPtrWillBeRawPtr<EventListener> listener)
+    void setOnmessage(RawPtr<EventListener> listener)
     {
         setAttributeEventListener(EventTypeNames::message, listener);
         start();