Make TopDocumentRootScrollerController store Page instead of FrameHost

third_party/WebKit/Source/core/page/scrolling/TopDocumentRootScrollerController.h

 // Copyright 2016 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.
 
 #ifndef TopDocumentRootScrollerController_h
 #define TopDocumentRootScrollerController_h
 
 #include "core/CoreExport.h"
 #include "core/page/scrolling/RootScrollerController.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class Element;
-class FrameHost;
+class Page;
 class GraphicsLayer;
 class PaintLayer;
 class RootFrameViewport;
 class ScrollStateCallback;
 class ScrollableArea;
 class ViewportScrollCallback;
 
 // This class manages the the page level aspects of the root scroller.  That
 // is, given all the iframes on a page and their individual root scrollers,
 // this class will determine which ultimate Element should be used as the root
 // scroller and ensures that Element is used to scroll browser controls and
 // provide overscroll effects.
 // TODO(bokan): This class is currently OOPIF unaware. crbug.com/642378.
 class CORE_EXPORT TopDocumentRootScrollerController
     : public GarbageCollected<TopDocumentRootScrollerController> {
  public:
-  static TopDocumentRootScrollerController* create(FrameHost&);
+  static TopDocumentRootScrollerController* create(Page&);
 
   DECLARE_TRACE();
 
   // This class needs to be informed of changes to compositing so that it can
   // update the compositor when the effective root scroller changes.
   void didUpdateCompositing();
 
   // PaintLayerScrollableAreas need to notify this class when they're being
   // disposed so that we can remove them as the root scroller.
   void didDisposeScrollableArea(ScrollableArea&);
@@ skipping 27 matching lines @@
   // this isn't necessarily the PLSA belonging to the root scroller Element's
   // LayoutBox.  If the root scroller is the documentElement then we use the
   // FrameView (or LayoutView if root-layer-scrolls).
   ScrollableArea* rootScrollerArea() const;
 
   // Returns the size we should use for the root scroller, accounting for top
   // controls adjustment and using the root FrameView.
   IntSize rootScrollerVisibleArea() const;
 
  private:
-  TopDocumentRootScrollerController(FrameHost&);
+  TopDocumentRootScrollerController(Page&);
 
   // Calculates the Element that should be the globalRootScroller. On a
   // simple page, this will simply the root frame's effectiveRootScroller but
   // if the root scroller is set to an iframe, this will then descend into
   // the iframe to find its effective root scroller.
   Element* findGlobalRootScrollerElement();
 
   // Should be called to ensure the correct element is currently set as the
   // global root scroller and that all appropriate state changes are made if
   // it changes.
   void recomputeGlobalRootScroller();
 
   Document* topDocument() const;
 
   void setNeedsCompositingInputsUpdateOnGlobalRootScroller();
 
   // The apply-scroll callback that moves browser controls and produces
   // overscroll effects. This class makes sure this callback is set on the
   // appropriate root scroller element.
   Member<ViewportScrollCallback> m_viewportApplyScroll;
 
   // The page level root scroller. i.e. The actual element for which
   // scrolling should move browser controls and produce overscroll glow. Once an
   // m_viewportApplyScroll has been created, it will always be set on this
   // Element.
   WeakMember<Element> m_globalRootScroller;
 
-  WeakMember<FrameHost> m_frameHost;
+  WeakMember<Page> m_page;

[haraken, 2017/03/08 06:15:48]

Not related to this CL, I don't understand why this pointer needs to be weak.
TopDocumentRootScrollerController and Page should live and die at the same time,
so this could just be a Member<Page>.

[sashab, 2017/03/08 23:39:31]

Haha, I thought the same thing when I saw this! Let me land it in a follow-up
patch, in case it causes test failures.

 };
 
 }  // namespace blink
 
 #endif  // RootScrollerController_h