Rename LifecycleObserver<T>::dispose() as clearContext()

Source/platform/LifecycleObserver.h

Index: Source/platform/LifecycleObserver.h
diff --git a/Source/platform/LifecycleObserver.h b/Source/platform/LifecycleObserver.h
index 3295d819579d6bb3fb02d801ac14e84aae4f7fa2..30c65bd12f74a3e7ecb33a8af31ae69b375f115c 100644
--- a/Source/platform/LifecycleObserver.h
+++ b/Source/platform/LifecycleObserver.h
@@ -40,7 +40,7 @@ public:
 #if !ENABLE(OILPAN)
     virtual ~LifecycleObserver()
     {
-        dispose();
+        clearContext();
     }
 #endif
 
@@ -52,11 +52,6 @@ public:
 
     virtual void contextDestroyed() { }
 
-    void dispose()
-    {
-        setContext(nullptr);
-    }
-
     Context* lifecycleContext() const { return m_lifecycleContext; }
     void clearLifecycleContext() { m_lifecycleContext = nullptr; }
 
@@ -69,6 +64,11 @@ protected:
 
     void setContext(Context*);
 
+    void clearContext()
+    {
+        setContext(nullptr);
+    }
+
 private:
     RawPtrWillBeWeakMember<Context> m_lifecycleContext;
 };