Remove more oilpan.

sky/engine/core/fetch/MemoryCache.h

Index: sky/engine/core/fetch/MemoryCache.h
diff --git a/sky/engine/core/fetch/MemoryCache.h b/sky/engine/core/fetch/MemoryCache.h
index 6d19b4a893d1a1fc4e7e2e4f47bf47aa3ac6537d..b8a0352896d1d6d5a7cf3f150013ce97a186feca 100644
--- a/sky/engine/core/fetch/MemoryCache.h
+++ b/sky/engine/core/fetch/MemoryCache.h
@@ -74,7 +74,7 @@ enum UpdateReason {
 // MemoryCacheEntry class is used only in MemoryCache class, but we don't make
 // MemoryCacheEntry class an inner class of MemoryCache because of dependency
 // from MemoryCacheLRUList.
-class MemoryCacheEntry final : public DummyBase<MemoryCacheEntry> {
+class MemoryCacheEntry final {
 public:
     static PassOwnPtr<MemoryCacheEntry> create(Resource* resource) { return adoptPtr(new MemoryCacheEntry(resource)); }
     void trace(Visitor*);
@@ -124,8 +124,8 @@ WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(blink::MemoryCacheLRUList);
 
 namespace blink {
 
-class MemoryCache final : public DummyBase<MemoryCache> {
-    WTF_MAKE_NONCOPYABLE(MemoryCache); WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
+class MemoryCache final {
+    WTF_MAKE_NONCOPYABLE(MemoryCache); WTF_MAKE_FAST_ALLOCATED;
 public:
     static PassOwnPtr<MemoryCache> create();
     ~MemoryCache();