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

Source/modules/filesystem/DevToolsHostFileSystem.h

Index: Source/modules/filesystem/DevToolsHostFileSystem.h
diff --git a/Source/modules/filesystem/DevToolsHostFileSystem.h b/Source/modules/filesystem/DevToolsHostFileSystem.h
index bb9a46f784b6480c9c258c93a053be2002ddd1c8..8f73422572f3608a38e86023b0d4de5df25b9854 100644
--- a/Source/modules/filesystem/DevToolsHostFileSystem.h
+++ b/Source/modules/filesystem/DevToolsHostFileSystem.h
@@ -6,6 +6,7 @@
 #define DevToolsHostFileSystem_h
 
 #include "platform/heap/Handle.h"
+#include "wtf/Allocator.h"
 #include "wtf/text/WTFString.h"
 
 namespace blink {
@@ -14,12 +15,10 @@ class DOMFileSystem;
 class DevToolsHost;
 
 class DevToolsHostFileSystem {
+    STATIC_ONLY(DevToolsHostFileSystem);
 public:
     static DOMFileSystem* isolatedFileSystem(DevToolsHost&, const String& fileSystemName, const String& rootURL);
     static void upgradeDraggedFileSystemPermissions(DevToolsHost&, DOMFileSystem*);
-private:
-    DevToolsHostFileSystem();
-    ~DevToolsHostFileSystem();
 };
 
 } // namespace blink