Remove mainthread overhang painting code

Source/core/paint/FramePainter.cpp

 // Copyright 2014 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 "config.h"
 #include "core/paint/FramePainter.h"
 
 #include "core/dom/DocumentMarkerController.h"
 #include "core/fetch/MemoryCache.h"
 #include "core/frame/FrameView.h"
@@ skipping 28 matching lines @@
     if (!documentDirtyRect.isEmpty()) {
         TransformRecorder transformRecorder(*context, *m_frameView.layoutView(),
             AffineTransform::translation(m_frameView.x() - m_frameView.scrollX(), m_frameView.y() - m_frameView.scrollY()));
 
         ClipRecorder recorder(*context, *m_frameView.layoutView(), DisplayItem::ClipFrameToVisibleContentRect, LayoutRect(m_frameView.visibleContentRect()));
 
         documentDirtyRect.moveBy(-m_frameView.location() + m_frameView.scrollPosition());
         paintContents(context, documentDirtyRect);
     }
 
-    calculateAndPaintOverhangAreas(context, rect);
-
     // Now paint the scrollbars.
     if (!m_frameView.scrollbarsSuppressed() && (m_frameView.horizontalScrollbar() || m_frameView.verticalScrollbar())) {
         IntRect scrollViewDirtyRect = rect;
         IntRect visibleAreaWithScrollbars(m_frameView.location(), m_frameView.visibleContentRect(IncludeScrollbars).size());
         scrollViewDirtyRect.intersect(visibleAreaWithScrollbars);
         scrollViewDirtyRect.moveBy(-m_frameView.location());
 
         TransformRecorder transformRecorder(*context, *m_frameView.layoutView(),
             AffineTransform::translation(m_frameView.x(), m_frameView.y()));
 
@@ skipping 138 matching lines @@
     bool needsBackground = bar->isCustomScrollbar() && m_frameView.frame().isMainFrame();
     if (needsBackground) {
         IntRect toFill = bar->frameRect();
         toFill.intersect(rect);
         context->fillRect(toFill, m_frameView.baseBackgroundColor());
     }
 
     bar->paint(context, rect);
 }
 
-void FramePainter::paintOverhangAreas(GraphicsContext* context, const IntRect& horizontalOverhangArea, const IntRect& verticalOverhangArea, const IntRect& dirtyRect)
-{
-    if (m_frameView.frame().document()->printing())
-        return;
-
-    if (m_frameView.frame().isMainFrame()) {
-        if (m_frameView.frame().page()->chrome().client().paintCustomOverhangArea(context, horizontalOverhangArea, verticalOverhangArea, dirtyRect))
-            return;
-    }
-
-    paintOverhangAreasInternal(context, horizontalOverhangArea, verticalOverhangArea, dirtyRect);
-}
-
-void FramePainter::paintOverhangAreasInternal(GraphicsContext* context, const IntRect& horizontalOverhangRect, const IntRect& verticalOverhangRect, const IntRect& dirtyRect)
-{
-    ScrollbarTheme::theme()->paintOverhangBackground(context, horizontalOverhangRect, verticalOverhangRect, dirtyRect);
-    ScrollbarTheme::theme()->paintOverhangShadows(context, m_frameView.scrollOffset(), horizontalOverhangRect, verticalOverhangRect, dirtyRect);
-}
-
-void FramePainter::calculateAndPaintOverhangAreas(GraphicsContext* context, const IntRect& dirtyRect)
-{
-    IntRect horizontalOverhangRect;
-    IntRect verticalOverhangRect;
-    m_frameView.calculateOverhangAreasForPainting(horizontalOverhangRect, verticalOverhangRect);
-
-    if (dirtyRect.intersects(horizontalOverhangRect) || dirtyRect.intersects(verticalOverhangRect))
-        paintOverhangAreas(context, horizontalOverhangRect, verticalOverhangRect, dirtyRect);
-}
-
 } // namespace blink