[RootLayerScrolls] Get rid of ScrollbarManager super-class

ScrollbarManager is now PLSA-specific.

BUG=823365
R=skobes@chromium.org,pdr@chromium.org

Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: Ia872266afb330836c10f6e36dce3e756a5895734
Reviewed-on: https://chromium-review.googlesource.com/1110881Reviewed-by: Steve Kobes <skobes@chromium.org>
Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Stefan Zager <szager@chromium.org>
Cr-Commit-Position: refs/heads/master@{#569442}

third_party/blink/renderer/core/paint/BUILD.gn

@@ -201,8 +201,6 @@ blink_core_sources("paint") {
     "scroll_recorder.h",
     "scrollable_area_painter.cc",
     "scrollable_area_painter.h",
-    "scrollbar_manager.cc",
-    "scrollbar_manager.h",
     "scrollbar_painter.cc",
     "scrollbar_painter.h",
     "selection_painting_utils.cc",

third_party/blink/renderer/core/paint/paint_layer_scrollable_area.cc

@@ -2334,20 +2334,6 @@ void PaintLayerScrollableArea::GetTickmarks(Vector<IntRect>& tickmarks) const {
     tickmarks = ToLayoutView(GetLayoutBox())->GetTickmarks();
 }
 
-PaintLayerScrollableArea*
-PaintLayerScrollableArea::ScrollbarManager::ScrollableArea() {
-  return ToPaintLayerScrollableArea(scrollable_area_.Get());
-}
-
-void PaintLayerScrollableArea::ScrollbarManager::DestroyDetachedScrollbars() {
-  DCHECK(!h_bar_is_attached_ || h_bar_);
-  DCHECK(!v_bar_is_attached_ || v_bar_);
-  if (h_bar_ && !h_bar_is_attached_)
-    DestroyScrollbar(kHorizontalScrollbar);
-  if (v_bar_ && !v_bar_is_attached_)
-    DestroyScrollbar(kVerticalScrollbar);
-}
-
 void PaintLayerScrollableArea::ScrollbarManager::SetHasHorizontalScrollbar(
     bool has_scrollbar) {
   if (has_scrollbar) {
@@ -2444,6 +2430,28 @@ void PaintLayerScrollableArea::ScrollbarManager::DestroyScrollbar(
   scrollbar = nullptr;
 }
 
+void PaintLayerScrollableArea::ScrollbarManager::DestroyDetachedScrollbars() {
+  DCHECK(!h_bar_is_attached_ || h_bar_);
+  DCHECK(!v_bar_is_attached_ || v_bar_);
+  if (h_bar_ && !h_bar_is_attached_)
+    DestroyScrollbar(kHorizontalScrollbar);
+  if (v_bar_ && !v_bar_is_attached_)
+    DestroyScrollbar(kVerticalScrollbar);
+}
+
+void PaintLayerScrollableArea::ScrollbarManager::Dispose() {
+  h_bar_is_attached_ = v_bar_is_attached_ = 0;
+  DestroyScrollbar(kHorizontalScrollbar);
+  DestroyScrollbar(kVerticalScrollbar);
+}
+
+void PaintLayerScrollableArea::ScrollbarManager::Trace(
+    blink::Visitor* visitor) {
+  visitor->Trace(scrollable_area_);
+  visitor->Trace(h_bar_);
+  visitor->Trace(v_bar_);
+}
+
 uint64_t PaintLayerScrollableArea::Id() const {
   return DOMNodeIds::IdForNode(GetLayoutBox()->GetNode());
 }

third_party/blink/renderer/core/paint/paint_layer_scrollable_area.h

@@ -51,7 +51,6 @@
 #include "third_party/blink/renderer/core/page/scrolling/sticky_position_scrolling_constraints.h"
 #include "third_party/blink/renderer/core/paint/paint_invalidation_capable_scrollable_area.h"
 #include "third_party/blink/renderer/core/paint/paint_layer_fragment.h"
-#include "third_party/blink/renderer/core/paint/scrollbar_manager.h"
 #include "third_party/blink/renderer/platform/heap/handle.h"
 #include "third_party/blink/renderer/platform/scroll/scroll_types.h"
 
@@ -120,7 +119,7 @@ class CORE_EXPORT PaintLayerScrollableArea final
   friend class Internals;
 
  private:
-  class ScrollbarManager : public blink::ScrollbarManager {
+  class ScrollbarManager {
     DISALLOW_NEW();
 
     // Helper class to manage the life cycle of Scrollbar objects.  Some layout
@@ -136,19 +135,43 @@ class CORE_EXPORT PaintLayerScrollableArea final
     // previously "deleted" scrollbar will be restored, rather than constructing
     // a new one.
    public:
-    ScrollbarManager(PaintLayerScrollableArea& scroller)
-        : blink::ScrollbarManager(scroller) {}
+    ScrollbarManager(PaintLayerScrollableArea& scrollable_area)
+        : scrollable_area_(scrollable_area),
+          h_bar_is_attached_(0),
+          v_bar_is_attached_(0) {}
+
+    PaintLayerScrollableArea* ScrollableArea() const {
+      return scrollable_area_.Get();
+    }
+    Scrollbar* HorizontalScrollbar() const {
+      return h_bar_is_attached_ ? h_bar_.Get() : nullptr;
+    }
+    Scrollbar* VerticalScrollbar() const {
+      return v_bar_is_attached_ ? v_bar_.Get() : nullptr;
+    }
+    bool HasHorizontalScrollbar() const { return HorizontalScrollbar(); }
+    bool HasVerticalScrollbar() const { return VerticalScrollbar(); }
+
+    void SetHasHorizontalScrollbar(bool has_scrollbar);
+    void SetHasVerticalScrollbar(bool has_scrollbar);
+
+    Scrollbar* CreateScrollbar(ScrollbarOrientation);
+    void DestroyDetachedScrollbars();
+    void Dispose();
 
-    void SetHasHorizontalScrollbar(bool has_scrollbar) override;
-    void SetHasVerticalScrollbar(bool has_scrollbar) override;
+    void Trace(blink::Visitor*);
 
-    void DestroyDetachedScrollbars();
-    Scrollbar* CreateScrollbar(ScrollbarOrientation) override;
+   private:
+    void DestroyScrollbar(ScrollbarOrientation);
+
+    Member<PaintLayerScrollableArea> scrollable_area_;
 
-   protected:
-    void DestroyScrollbar(ScrollbarOrientation) override;
+    // The scrollbars associated with scrollable_area_. Both can nullptr.
+    Member<Scrollbar> h_bar_;
+    Member<Scrollbar> v_bar_;
 
-    PaintLayerScrollableArea* ScrollableArea();
+    unsigned h_bar_is_attached_ : 1;
+    unsigned v_bar_is_attached_ : 1;
   };
 
  public:

third_party/blink/renderer/core/paint/scrollbar_manager.cc

-// 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.
-
-#include "third_party/blink/renderer/core/paint/scrollbar_manager.h"
-
-namespace blink {
-
-ScrollbarManager::ScrollbarManager(ScrollableArea& scrollable_area)
-    : scrollable_area_(&scrollable_area),
-      h_bar_is_attached_(0),
-      v_bar_is_attached_(0) {}
-
-void ScrollbarManager::Trace(blink::Visitor* visitor) {
-  visitor->Trace(scrollable_area_);
-  visitor->Trace(h_bar_);
-  visitor->Trace(v_bar_);
-}
-
-void ScrollbarManager::Dispose() {
-  h_bar_is_attached_ = v_bar_is_attached_ = 0;
-  DestroyScrollbar(kHorizontalScrollbar);
-  DestroyScrollbar(kVerticalScrollbar);
-}
-
-}  // namespace blink

third_party/blink/renderer/core/paint/scrollbar_manager.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 THIRD_PARTY_BLINK_RENDERER_CORE_PAINT_SCROLLBAR_MANAGER_H_
-#define THIRD_PARTY_BLINK_RENDERER_CORE_PAINT_SCROLLBAR_MANAGER_H_
-
-#include "third_party/blink/renderer/core/core_export.h"
-#include "third_party/blink/renderer/platform/scroll/scrollable_area.h"
-
-namespace blink {
-
-class CORE_EXPORT ScrollbarManager {
-  DISALLOW_NEW();
-
-  // Helper class to manage the life cycle of Scrollbar objects.
- public:
-  ScrollbarManager(ScrollableArea&);
-
-  void Dispose();
-
-  Scrollbar* HorizontalScrollbar() const {
-    return h_bar_is_attached_ ? h_bar_.Get() : nullptr;
-  }
-  Scrollbar* VerticalScrollbar() const {
-    return v_bar_is_attached_ ? v_bar_.Get() : nullptr;
-  }
-  bool HasHorizontalScrollbar() const { return HorizontalScrollbar(); }
-  bool HasVerticalScrollbar() const { return VerticalScrollbar(); }
-
-  // These functions are used to create/destroy scrollbars.
-  virtual void SetHasHorizontalScrollbar(bool has_scrollbar) = 0;
-  virtual void SetHasVerticalScrollbar(bool has_scrollbar) = 0;
-
-  virtual void Trace(blink::Visitor*);
-
- protected:
-  // TODO(ymalik): This can be made non-virtual since there's a lot of
-  // common code in subclasses.
-  virtual Scrollbar* CreateScrollbar(ScrollbarOrientation) = 0;
-  virtual void DestroyScrollbar(ScrollbarOrientation) = 0;
-
- protected:
-  Member<ScrollableArea> scrollable_area_;
-
-  // The scrollbars associated with m_scrollableArea. Both can nullptr.
-  Member<Scrollbar> h_bar_;
-  Member<Scrollbar> v_bar_;
-
-  unsigned h_bar_is_attached_ : 1;
-  unsigned v_bar_is_attached_ : 1;
-};
-
-}  // namespace blink
-
-#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_PAINT_SCROLLBAR_MANAGER_H_