Make sure pages that are closing but not yet closed are still suspended.

third_party/WebKit/Source/core/page/Page.h

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2013 Apple Inc. All rights
  * reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  *
  * 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.
@@ skipping 42 matching lines @@
 class ContextMenuController;
 class Document;
 class DragCaretController;
 class DragController;
 class EditorClient;
 class FocusController;
 class Frame;
 class FrameHost;
 class PluginData;
 class PointerLockController;
+class ScopedPageSuspender;
 class ScrollingCoordinator;
 class Settings;
 class SpellCheckerClient;
 class ValidationMessageClient;
 class WebLayerTreeView;
 
 typedef uint64_t LinkHash;
 
 float deviceScaleFactor(LocalFrame*);
 
@@ skipping 24 matching lines @@
 
   static Page* create(PageClients& pageClients) {
     return new Page(pageClients);
   }
 
   // An "ordinary" page is a fully-featured page owned by a web view.
   static Page* createOrdinary(PageClients&);
 
   ~Page() override;
 
-  void willBeClosed();
+  void closeSoon();
+  bool isClosing() const { return m_isClosing; }
 
   using PageSet = PersistentHeapHashSet<WeakMember<Page>>;
 
   // Return the current set of full-fledged, ordinary pages.
   // Each created and owned by a WebView.
   //
   // This set does not include Pages created for other, internal purposes
   // (SVGImages, inspector overlays, page popups etc.)
   static PageSet& ordinaryPages();
 
@@ skipping 62 matching lines @@
   Deprecation& deprecation() { return m_deprecation; }
   HostsUsingFeatures& hostsUsingFeatures() { return m_hostsUsingFeatures; }
 
   void setTabKeyCyclesThroughElements(bool b) {
     m_tabKeyCyclesThroughElements = b;
   }
   bool tabKeyCyclesThroughElements() const {
     return m_tabKeyCyclesThroughElements;
   }
 
-  // DefersLoading is used to delay loads during modal dialogs.
-  // Modal dialogs are supposed to freeze all background processes
-  // in the page, including prevent additional loads from staring/continuing.
-  void setSuspended(bool);
+  // Suspension is used to implement the "Optionally, pause while waiting for
+  // the user to acknowledge the message" step of simple dialog processing:
+  // https://html.spec.whatwg.org/multipage/webappapis.html#simple-dialogs
+  //
+  // Per https://html.spec.whatwg.org/multipage/webappapis.html#pause, no loads
+  // are allowed to start/continue in this state, and all background processing
+  // is also suspended.
   bool suspended() const { return m_suspended; }
 
   void setPageScaleFactor(float);
   float pageScaleFactor() const;
 
   float deviceScaleFactor() const { return m_deviceScaleFactor; }
   void setDeviceScaleFactor(float);
 
   static void allVisitedStateChanged(bool invalidateVisitedLinkHashes);
   static void visitedStateChanged(LinkHash visitedHash);
@@ skipping 17 matching lines @@
   static void networkStateChanged(bool online);
 
   DECLARE_TRACE();
 
   void layerTreeViewInitialized(WebLayerTreeView&);
   void willCloseLayerTreeView(WebLayerTreeView&);
 
   void willBeDestroyed();
 
  private:
+  friend class ScopedPageSuspender;
+
   explicit Page(PageClients&);
 
   void initGroup();
 
   // SettingsDelegate overrides.
   void settingsChanged(SettingsDelegate::ChangeType) override;
 
+  // ScopedPageSuspender helpers.
+  void setSuspended(bool);
+
   Member<PageAnimator> m_animator;
   const Member<AutoscrollController> m_autoscrollController;
   Member<ChromeClient> m_chromeClient;
   const Member<DragCaretController> m_dragCaretController;
   const Member<DragController> m_dragController;
   const Member<FocusController> m_focusController;
   const Member<ContextMenuController> m_contextMenuController;
   const Member<PointerLockController> m_pointerLockController;
   Member<ScrollingCoordinator> m_scrollingCoordinator;
 
@@ skipping 15 matching lines @@
 
   EditorClient* const m_editorClient;
   SpellCheckerClient* const m_spellCheckerClient;
   Member<ValidationMessageClient> m_validationMessageClient;
 
   UseCounter m_useCounter;
   Deprecation m_deprecation;
   HostsUsingFeatures m_hostsUsingFeatures;
 
   bool m_openedByDOM;
+  // Set to true when window.close() has been called and the Page will be
+  // destroyed. The browsing contexts in this page should no longer be
+  // discoverable via JS.
+  // TODO(dcheng): Try to remove |DOMWindow::m_windowIsClosing| in favor of
+  // this. However, this depends on resolving https://crbug.com/674641
+  bool m_isClosing;
 
   bool m_tabKeyCyclesThroughElements;
   bool m_suspended;
 
   float m_deviceScaleFactor;
 
   PageVisibilityState m_visibilityState;
 
   bool m_isCursorVisible;
 
 #if ENABLE(ASSERT)
   bool m_isPainting;
 #endif
 
   // A pointer to all the interfaces provided to in-process Frames for this
   // Page.
   // FIXME: Most of the members of Page should move onto FrameHost.
   Member<FrameHost> m_frameHost;
 };
 
 extern template class CORE_EXTERN_TEMPLATE_EXPORT Supplement<Page>;
 
 }  // namespace blink
 
 #endif  // Page_h