Extract a DOMWindow interface from LocalDOMWindow and use it in the idl.

Source/modules/filesystem/DOMWindowFileSystem.h

Index: Source/modules/filesystem/DOMWindowFileSystem.h
diff --git a/Source/modules/filesystem/DOMWindowFileSystem.h b/Source/modules/filesystem/DOMWindowFileSystem.h
index 535ae170842dab2b04ba5fc88d9b012056298ff7..98a42e865e7065c20a06beace3981a047798328d 100644
--- a/Source/modules/filesystem/DOMWindowFileSystem.h
+++ b/Source/modules/filesystem/DOMWindowFileSystem.h
@@ -31,15 +31,15 @@
 
 namespace blink {
 
-class LocalDOMWindow;
+class DOMWindow;
 class EntryCallback;
 class ErrorCallback;
 class FileSystemCallback;
 
 class DOMWindowFileSystem {
 public:
-    static void webkitRequestFileSystem(LocalDOMWindow&, int type, long long size, FileSystemCallback*, ErrorCallback*);
-    static void webkitResolveLocalFileSystemURL(LocalDOMWindow&, const String&, EntryCallback*, ErrorCallback*);
+    static void webkitRequestFileSystem(DOMWindow&, int type, long long size, FileSystemCallback*, ErrorCallback*);
+    static void webkitResolveLocalFileSystemURL(DOMWindow&, const String&, EntryCallback*, ErrorCallback*);
 
     // They are placed here and in all capital letters so they can be checked against the constants in the
     // IDL at compile time.