Deleted Widget/FrameViewBase

third_party/WebKit/Source/core/frame/FrameView.h

Index: third_party/WebKit/Source/core/frame/FrameView.h
diff --git a/third_party/WebKit/Source/core/frame/FrameView.h b/third_party/WebKit/Source/core/frame/FrameView.h
index fd20ad1e8de777f48bef6fb2724f840745adbab0..1084434b5e6c6eaa65a46973fea511d235469238 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.h
+++ b/third_party/WebKit/Source/core/frame/FrameView.h
@@ -40,7 +40,6 @@
 #include "core/paint/PaintInvalidationCapableScrollableArea.h"
 #include "core/paint/PaintPhase.h"
 #include "core/paint/ScrollbarManager.h"
-#include "platform/FrameViewBase.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/animation/CompositorAnimationHost.h"
 #include "platform/animation/CompositorAnimationTimeline.h"
@@ -102,7 +101,6 @@ typedef unsigned long long DOMTimeStamp;
 
 class CORE_EXPORT FrameView final
     : public GarbageCollectedFinalized<FrameView>,
-      public FrameViewBase,
       public FrameOrPlugin,
       public PaintInvalidationCapableScrollableArea {
   USING_GARBAGE_COLLECTED_MIXIN(FrameView);
@@ -126,7 +124,7 @@ class CORE_EXPORT FrameView final
   int Width() const { return frame_rect_.Width(); }
   int Height() const { return frame_rect_.Height(); }
   IntSize Size() const { return frame_rect_.Size(); }
-  IntPoint Location() const override { return frame_rect_.Location(); }
+  IntPoint Location() const { return frame_rect_.Location(); }
   void Resize(int width, int height) {
     SetFrameRect(IntRect(frame_rect_.X(), frame_rect_.Y(), width, height));
   }
@@ -479,9 +477,6 @@ class CORE_EXPORT FrameView final
   // and repaints to the host window in the window's coordinate space.
   PlatformChromeClient* GetChromeClient() const;
 
-  typedef HeapHashSet<Member<FrameOrPlugin>> ChildrenSet;
-  typedef HeapHashSet<Member<Scrollbar>> ScrollbarsSet;
-
   // Functions for child manipulation and inspection.
   bool IsSelfVisible() const {
     return self_visible_;
@@ -499,10 +494,12 @@ class CORE_EXPORT FrameView final
   FrameView* Root() const;
   void RemoveChild(FrameOrPlugin*);
   void AddChild(FrameOrPlugin*);
+  typedef HeapHashSet<Member<FrameOrPlugin>> ChildrenSet;
   const ChildrenSet& Children() const { return children_; }
-  void RemoveScrollbar(Scrollbar*);
-  void AddScrollbar(Scrollbar*);
-  const ScrollbarsSet& Scrollbars() const { return scrollbars_; }
+  // Custom PaintLayer scrollbars need to be called with StyleChanged
+  // whenever window focus is changed.
+  void RemovePaintScrollbar(Scrollbar*);

[dcheng, 2017/05/09 08:05:55]

Is the term "PaintScrollbar" used elsewhere in Chrome code as a noun?
It's not clear to me what a custom PaintLayer scrollbar is.

[joelhockey, 2017/05/10 04:17:13]

No, I don't believe PaintScrollbar is used elsewhere.  PaintLayer Scrollbar is
to Scrollbar as PaintLayerScrollableArea is to ScrollableArea.

PaintLayerScrollableArea (PLSA) and ScrollableArea are parallel classes which
are containers of scrollbars.  See http://bit.ly/root-layer-scrolling for more
info.

It turns out that FrameView has been holding the scrollbars (horizontal and / or
vertical) of both ScrollableArea (itself) and PLSA.  When there are scrollbars
with custom CSS, then all (up to 4) scrollbars need to be notified when focus
changes.  The 2 scrollbars that are part of ScrollableArea already get looked
after in FrameView::RecalculateCustomScrollbarStyle, so the old
FrameView::scrollbars_ container only really needs to hold references to the 2
scrollbars in PLSA.

So these names could be:

AddPaintLayerScrollableAreaScrollbar
RemovePaintLayerScrollableAreaScrollbar

But I went with the shorter:

AddPaintScrollbar
RemovePaintScrollbar

I don't mind changing the name to anything else.

Ideally, this parallel scrollbar container setup wouldn't exist, and there are
plans to remove it.

[dcheng, 2017/05/10 07:27:00]

Unless I'm missing something, I think the original names might be the clearest.
The caller can pass in a scrollbar created by LayoutScrollbar::Create() or
Scrollbar::Create(): neither of these mentions "Paint", so it's not clear how
"Paint" relates (I guess it's an implementation detail in this case, but not a
particularly obvious one?)

+  void AddPaintScrollbar(Scrollbar*);
 
   // If the scroll view does not use a native widget, then it will have
   // cross-platform Scrollbars. These functions can be used to obtain those
@@ -649,6 +646,9 @@ class CORE_EXPORT FrameView final
 
   IntRect ConvertToRootFrame(const IntRect&) const;
   IntPoint ConvertToRootFrame(const IntPoint&) const;
+  IntRect ConvertFromRootFrame(const IntRect&) const;
+  IntPoint ConvertFromRootFrame(const IntPoint&) const override;
+  FloatPoint ConvertFromRootFrame(const FloatPoint&) const;
   IntPoint ConvertSelfToChild(const IntPoint&, const IntPoint&) const;
 
   // Handles painting of the contents of the view as well as the scrollbars.
@@ -1144,7 +1144,7 @@ class CORE_EXPORT FrameView final
   bool vertical_scrollbar_lock_;
 
   ChildrenSet children_;
-  ScrollbarsSet scrollbars_;
+  HeapHashSet<Member<Scrollbar>> paint_scrollbars_;
 
   ScrollOffset pending_scroll_delta_;
   ScrollOffset scroll_offset_;
@@ -1262,11 +1262,6 @@ inline void FrameView::IncrementVisuallyNonEmptyPixelCount(
 }
 
 DEFINE_TYPE_CASTS(FrameView,
-                  FrameViewBase,
-                  frameViewBase,
-                  frameViewBase->IsFrameView(),
-                  frameViewBase.IsFrameView());
-DEFINE_TYPE_CASTS(FrameView,
                   FrameOrPlugin,
                   frame_or_plugin,
                   frame_or_plugin->IsFrameView(),