Oilpan: Move all supplements of Page, Document, and WorkerClients to the managed heap.

Source/modules/screen_orientation/ScreenOrientationController.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "config.h"
 #include "modules/screen_orientation/ScreenOrientationController.h"
 
 #include "core/dom/Document.h"
 #include "core/events/Event.h"
 #include "core/frame/DOMWindow.h"
 #include "core/frame/Screen.h"
 #include "modules/screen_orientation/ScreenOrientationDispatcher.h"
 
 namespace WebCore {
 
 ScreenOrientationController::~ScreenOrientationController()
 {
     ScreenOrientationDispatcher::instance().removeController(this);

[haraken, 2014/04/30 02:41:22]

I think you need to change ScreenOrientationDispatcher::m_controllers to a hash
set of weak members.

It's not a good thing to let some object hold a raw pointer to GarbageCollected
objects. Let's confirm that for all GarbageCollected classes in this CL, no
object is holding a raw pointer to the GarbageCollected objects.

[zerny-chromium, 2014/04/30 08:29:34]

In the transition we can't avoid some cases of raw pointers to GC'ed objects,
which is why the plugin does not report such errors yet.

In the present case, m_controllers can't immediately be made weak because the
ScreenOrientationDispatcher is off heap. Moving it and updating the logic is not
completely trivial, so I'd like to postpone that to a followup CL. (On Oilpan we
have different assumptions regarding when removeController will be called (ie,
it is never called under dispatching)).

The current code should be safe since the dispatcher does not access any of its
controllers during removal and is guarantied to outlive the controllers.

 }
 
 ScreenOrientationController& ScreenOrientationController::from(Document& document)
 {
     ScreenOrientationController* controller = static_cast<ScreenOrientationController*>(DocumentSupplement::from(document, supplementName()));
     if (!controller) {
         controller = new ScreenOrientationController(document);
-        DocumentSupplement::provideTo(document, supplementName(), adoptPtr(controller));
+        DocumentSupplement::provideTo(document, supplementName(), adoptPtrWillBeNoop(controller));
     }
     return *controller;
 }
 
 ScreenOrientationController::ScreenOrientationController(Document& document)
     : m_document(document)
     , m_orientation(blink::WebScreenOrientationPortraitPrimary)
 {
     // FIXME: We should listen for screen orientation change events only when the page is visible.
     ScreenOrientationDispatcher::instance().addController(this);
@@ skipping 15 matching lines @@
 void ScreenOrientationController::didChangeScreenOrientation(blink::WebScreenOrientationType orientation)
 {
     if (orientation == m_orientation)
         return;
 
     m_orientation = orientation;
     dispatchOrientationChangeEvent();
 }
 
 } // namespace WebCore