Copy Page::ordinaryPages() before undeferring loads.

third_party/WebKit/Source/core/page/ScopedPageLoadDeferrer.cpp

 /*
  * Copyright (C) 2006, 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 19 matching lines @@
 #include "wtf/Vector.h"
 
 namespace blink {
 
 namespace {
 
 unsigned s_deferralCount = 0;
 
 void setDefersLoading(bool isDeferred)
 {
+    HeapVector<Member<Page>> pages;

[dcheng, 2016/08/15 21:57:27]

I'm not sure if it's more standard for this to be Member (since that matches
what the old RefPtr semantics would have been: this collection strongly keeps it
live) or WeakMember (to match the type of PageSet). In theory, WeakMember here
is OK: I don't think Oilpan GC can collect in the middle here, but it's seems a
bit harder to understand.

So I ended up going with Member.

[haraken, 2016/08/15 22:01:47]

HeapVector<Member<>> makes sense. We don't want to use WeakMember unless there's
any reason to do so (because of the overhead).

     for (const auto& page : Page::ordinaryPages())
+        pages.append(page);

[haraken, 2016/08/15 22:01:47]

Shall we add a comment and mention why we're copying?

[dcheng, 2016/08/15 22:34:28]

Done.

+    for (const auto& page : pages)
         page->setDefersLoading(isDeferred);
 }
 
 } // namespace
 
 ScopedPageLoadDeferrer::ScopedPageLoadDeferrer()
 {
     if (++s_deferralCount > 1)
         return;
 
     setDefersLoading(true);
     Platform::current()->currentThread()->scheduler()->suspendTimerQueue();
 }
 
 ScopedPageLoadDeferrer::~ScopedPageLoadDeferrer()
 {
     if (--s_deferralCount > 0)
         return;
 
     setDefersLoading(false);
     Platform::current()->currentThread()->scheduler()->resumeTimerQueue();
 }
 
 bool ScopedPageLoadDeferrer::isActive()
 {
     return s_deferralCount > 0;
 }
 
 } // namespace blink