Move LocalFileSystem to hang off LocalFrame instead of Page.

Source/modules/filesystem/LocalFileSystem.h

Index: Source/modules/filesystem/LocalFileSystem.h
diff --git a/Source/modules/filesystem/LocalFileSystem.h b/Source/modules/filesystem/LocalFileSystem.h
index f13a782f4c778da0a4f7951bb445eb35bec9f308..d871048423fc119f3cbd348702ca94da295148fe 100644
--- a/Source/modules/filesystem/LocalFileSystem.h
+++ b/Source/modules/filesystem/LocalFileSystem.h
@@ -31,7 +31,6 @@
 #ifndef LocalFileSystem_h
 #define LocalFileSystem_h
 
-#include "core/page/Page.h"
 #include "core/workers/WorkerClients.h"
 #include "platform/FileSystemType.h"
 #include "wtf/Forward.h"
@@ -43,12 +42,13 @@ class AsyncFileSystemCallbacks;
 class CallbackWrapper;
 class FileSystemClient;
 class ExecutionContext;
+class KURL;
+class LocalFrame;
 
-class LocalFileSystem FINAL : public NoBaseWillBeGarbageCollectedFinalized<LocalFileSystem>, public WillBeHeapSupplement<Page>, public WillBeHeapSupplement<WorkerClients> {
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(LocalFileSystem);
+class LocalFileSystem FINAL : public Supplement<LocalFrame>, public Supplement<WorkerClients> {

[haraken, 2014/06/07 02:33:16]

Ian (or oilpan experts): WorkerClients is already on-heap. Is it safe for an
off-heap object (i.e., LocalFileSystem) to derive WorkerClients as
Supplement<WorkerClients>, not HeapSupplement<WorkerClients> ? In my
understanding, if WorkerClients is on-heap, all supplementing objects need to be
on-heap.

If my understanding is correct, it's tricky to make this CL workable, because
LocalFileSystem supplements both LocalFrame (off-heap) and WorkerClients
(on-heap). Probably do we need to move LocalFrame to the heap so that we can
make LocalFileSystem on-heap?

     WTF_MAKE_NONCOPYABLE(LocalFileSystem);
 public:
-    static PassOwnPtrWillBeRawPtr<LocalFileSystem> create(PassOwnPtr<FileSystemClient>);
+    static PassOwnPtr<LocalFileSystem> create(PassOwnPtr<FileSystemClient>);
     virtual ~LocalFileSystem();
 
     void resolveURL(ExecutionContext*, const KURL&, PassOwnPtr<AsyncFileSystemCallbacks>);
@@ -62,7 +62,7 @@ public:
 
     virtual void trace(Visitor* visitor) OVERRIDE
     {
-        WillBeHeapSupplement<Page>::trace(visitor);
+        WillBeHeapSupplement<LocalFrame>::trace(visitor);

[sof, 2014/06/06 20:32:41]

s/WillBeHeapSupplement/Supplement/

         WillBeHeapSupplement<WorkerClients>::trace(visitor);

[sof, 2014/06/06 20:32:41]

s/WillBeHeapSupplement/Supplement/

     }