Remove FrameViewBase as base class of PluginView.

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

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 1485 matching lines @@
 void FrameView::UpdateGeometries() {
   Vector<RefPtr<LayoutPart>> parts;
   CopyToVector(parts_, parts);
 
   for (auto part : parts) {
     // Script or plugins could detach the frame so abort processing if that
     // happens.
     if (GetLayoutViewItem().IsNull())
       break;
 
-    if (FrameViewBase* frame_view_base = part->PluginOrFrame()) {
-      if (frame_view_base->IsFrameView()) {
-        FrameView* frame_view = ToFrameView(frame_view_base);
+    if (part->GetFrameOrPlugin()) {
+      if (FrameView* frame_view = part->ChildFrameView()) {
         bool did_need_layout = frame_view->NeedsLayout();
         part->UpdateGeometry();
         if (!did_need_layout && !frame_view->ShouldThrottleRendering())
           frame_view->CheckDoesNotNeedLayout();
       } else {
         part->UpdateGeometry();
       }
     }
   }
 }
@@ skipping 3815 matching lines @@
 void FrameView::SetAnimationHost(
     std::unique_ptr<CompositorAnimationHost> host) {
   animation_host_ = std::move(host);
 }
 
 LayoutUnit FrameView::CaretWidth() const {
   return LayoutUnit(GetHostWindow()->WindowToViewportScalar(1));
 }
 
 }  // namespace blink