Replace FINAL and OVERRIDE with their C++11 counterparts in Source/core/[fetch|fileapi]

Source/core/fileapi/FileReader.cpp

Index: Source/core/fileapi/FileReader.cpp
diff --git a/Source/core/fileapi/FileReader.cpp b/Source/core/fileapi/FileReader.cpp
index 6030ba7ecb6a2139b47be062aa9681d46c5a2b2c..042e7cf31ef3a468f27b3707944ef32513589c1d 100644
--- a/Source/core/fileapi/FileReader.cpp
+++ b/Source/core/fileapi/FileReader.cpp
@@ -79,7 +79,7 @@ typedef PersistentHeapHashSetWillBeHeapHashSet<Member<FileReader> > FileReaderHa
 
 // FIXME: Oilpan: if ExecutionContext is moved to the heap, consider
 // making this object an ExecutionContext supplement (only.)
-class FileReader::ThrottlingController FINAL : public NoBaseWillBeGarbageCollectedFinalized<FileReader::ThrottlingController>, public WillBeHeapSupplement<LocalFrame>, public WillBeHeapSupplement<WorkerClients> {
+class FileReader::ThrottlingController final : public NoBaseWillBeGarbageCollectedFinalized<FileReader::ThrottlingController>, public WillBeHeapSupplement<LocalFrame>, public WillBeHeapSupplement<WorkerClients> {
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(FileReader::ThrottlingController);
 public:
     static ThrottlingController* from(ExecutionContext* context)