[part 1] Make classes and structures in modules/ fast-allocated.

Source/modules/filesystem/HTMLInputElementFileSystem.h

Index: Source/modules/filesystem/HTMLInputElementFileSystem.h
diff --git a/Source/modules/filesystem/HTMLInputElementFileSystem.h b/Source/modules/filesystem/HTMLInputElementFileSystem.h
index 526f67f2478abc9876818db8b5a6345371c9bfdc..7eb3145e5d8dda815770ef375c51eda5e095e34b 100644
--- a/Source/modules/filesystem/HTMLInputElementFileSystem.h
+++ b/Source/modules/filesystem/HTMLInputElementFileSystem.h
@@ -32,6 +32,7 @@
 #define HTMLInputElementFileSystem_h
 
 #include "modules/filesystem/EntriesCallback.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
@@ -39,12 +40,9 @@ class HTMLInputElement;
 class ExecutionContext;
 
 class HTMLInputElementFileSystem {
+    STATIC_ONLY(HTMLInputElementFileSystem);
 public:
     static EntryHeapVector webkitEntries(ExecutionContext*, HTMLInputElement&);
-
-private:
-    HTMLInputElementFileSystem();
-    ~HTMLInputElementFileSystem();
 };
 
 } // namespace blink