[Oilpan] [Reland] Migrate classes under core/fetch to Oilpan heap

Source/core/fetch/FetchContext.h

Index: Source/core/fetch/FetchContext.h
diff --git a/Source/core/fetch/FetchContext.h b/Source/core/fetch/FetchContext.h
index f912c2150aeab586e3ca81bb67def2a998cd1526..f2d05d9f9ad105e5f21df6f3213c7085acc5af67 100644
--- a/Source/core/fetch/FetchContext.h
+++ b/Source/core/fetch/FetchContext.h
@@ -54,7 +54,7 @@ enum FetchResourceType {
     FetchSubresource
 };
 
-class CORE_EXPORT FetchContext : public NoBaseWillBeGarbageCollectedFinalized<FetchContext> {
+class CORE_EXPORT FetchContext : public GarbageCollectedFinalized<FetchContext> {
     WTF_MAKE_NONCOPYABLE(FetchContext);
 public:
     static FetchContext& nullInstance();