Revert of Calculate paint invalidation rect for scrollbars

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
index 282ec669367b4182c74c08c441d105b5eceb4465..b7ea489f47a8bfc36198b4f6a6227cd1f5bbd721 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
@@ -199,9 +199,61 @@
     return layer()->hasCompositedLayerMapping() ? layer()->compositedLayerMapping()->layerForScrollCorner() : 0;
 }
 
-void PaintLayerScrollableArea::scrollControlWasSetNeedsPaintInvalidation()
-{
-    box().setMayNeedPaintInvalidation();
+void PaintLayerScrollableArea::invalidateScrollbarRect(Scrollbar* scrollbar, const IntRect& rect)
+{
+    // See crbug.com/343132.
+    DisableCompositingQueryAsserts disabler;
+
+    ASSERT(scrollbar == horizontalScrollbar() || scrollbar == verticalScrollbar());
+    ASSERT(scrollbar == horizontalScrollbar() ? !layerForHorizontalScrollbar() : !layerForVerticalScrollbar());
+
+    IntRect scrollRect = rect;
+    // If we are not yet inserted into the tree, there is no need to issue paint invaldiations.
+    if (!box().isLayoutView() && !box().parent())
+        return;
+
+    if (scrollbar == verticalScrollbar())
+        scrollRect.move(verticalScrollbarStart(0, box().size().width()), box().borderTop());
+    else
+        scrollRect.move(horizontalScrollbarStart(0), box().size().height() - box().borderBottom() - scrollbar->height());
+
+    if (scrollRect.isEmpty())
+        return;
+
+    LayoutRect paintInvalidationRect = LayoutRect(scrollRect);
+    box().flipForWritingMode(paintInvalidationRect);
+
+    IntRect intRect = pixelSnappedIntRect(paintInvalidationRect);
+
+    if (box().frameView()->isInPerformLayout()) {
+        addScrollbarDamage(scrollbar, intRect);
+    } else {
+        // FIXME: We should not allow paint invalidation out of paint invalidation state. crbug.com/457415
+        DisablePaintInvalidationStateAsserts disabler;
+        // We have invalidated the displayItemClient of the scrollbar, but for now we still need to
+        // invalidate the rectangles to trigger repaints.
+        box().invalidatePaintRectangleNotInvalidatingDisplayItemClients(LayoutRect(intRect));
+        box().invalidateDisplayItemClient(*scrollbar);
+    }
+}
+
+void PaintLayerScrollableArea::invalidateScrollCornerRect(const IntRect& rect)
+{
+    ASSERT(!layerForScrollCorner());
+
+    if (m_scrollCorner) {
+        // FIXME: We should not allow paint invalidation out of paint invalidation state. crbug.com/457415
+        DisablePaintInvalidationStateAsserts disabler;
+        DisableCompositingQueryAsserts compositingDisabler;
+        m_scrollCorner->invalidatePaintRectangle(LayoutRect(rect));
+        box().invalidateDisplayItemClientForNonCompositingDescendantsOf(*m_scrollCorner);
+    } else {
+        box().invalidateDisplayItemClient(box());
+    }
+    if (m_resizer) {
+        m_resizer->invalidatePaintRectangle(LayoutRect(rect));
+        box().invalidateDisplayItemClientForNonCompositingDescendantsOf(*m_resizer);
+    }
 }
 
 bool PaintLayerScrollableArea::shouldUseIntegerScrollOffset() const
@@ -984,8 +1036,8 @@
     if (hasScrollbar == hasHorizontalScrollbar())
         return;
 
-    setScrollbarNeedsPaintInvalidation(horizontalScrollbar());
-
+    if (!hasScrollbar && !layerForHorizontalScrollbar())
+        horizontalScrollbar()->invalidate();
 
     m_scrollbarManager.setHasHorizontalScrollbar(hasScrollbar);
 
@@ -995,7 +1047,10 @@
     if (hasVerticalScrollbar())
         verticalScrollbar()->styleChanged();
 
-    setScrollCornerNeedsPaintInvalidation();
+    // These are valid because we want to invalidate display item clients on the current backing.
+    DisablePaintInvalidationStateAsserts paintInvalidationAssertDisabler;
+    DisableCompositingQueryAsserts compositingAssertDisabler;
+    invalidateScrollCorner(scrollCornerRect());
 
     // Force an update since we know the scrollbars have changed things.
     if (box().document().hasAnnotatedRegions())
@@ -1007,7 +1062,8 @@
     if (hasScrollbar == hasVerticalScrollbar())
         return;
 
-    setScrollbarNeedsPaintInvalidation(verticalScrollbar());
+    if (!hasScrollbar && !layerForVerticalScrollbar())
+        verticalScrollbar()->invalidate();
 
     m_scrollbarManager.setHasVerticalScrollbar(hasScrollbar);
 
@@ -1017,7 +1073,10 @@
     if (hasVerticalScrollbar())
         verticalScrollbar()->styleChanged();
 
-    setScrollCornerNeedsPaintInvalidation();
+    // These are valid because we want to invalidate display item clients on the current backing.
+    DisablePaintInvalidationStateAsserts paintInvalidationAssertDisabler;
+    DisableCompositingQueryAsserts compositingAssertDisabler;
+    invalidateScrollCorner(scrollCornerRect());
 
     // Force an update since we know the scrollbars have changed things.
     if (box().document().hasAnnotatedRegions())
@@ -1439,9 +1498,9 @@
     m_canDetachScrollbars = detach ? 1 : 0;
     if (!detach) {
         if (m_hBar && !m_hBarIsAttached)
-            destroyScrollbar(HorizontalScrollbar);
+            destroyScrollbar(HorizontalScrollbar, true);
         if (m_vBar && !m_vBarIsAttached)
-            destroyScrollbar(VerticalScrollbar);
+            destroyScrollbar(VerticalScrollbar, true);
     }
 }
 
@@ -1497,15 +1556,17 @@
     return widget.release();
 }
 
-void PaintLayerScrollableArea::ScrollbarManager::destroyScrollbar(ScrollbarOrientation orientation)
+void PaintLayerScrollableArea::ScrollbarManager::destroyScrollbar(ScrollbarOrientation orientation, bool invalidate)
 {
     RefPtrWillBeMember<Scrollbar>& scrollbar = orientation == HorizontalScrollbar ? m_hBar : m_vBar;
     ASSERT(orientation == HorizontalScrollbar ? !m_hBarIsAttached: !m_vBarIsAttached);
     if (!scrollbar)
         return;
 
-    m_scrollableArea->setScrollbarNeedsPaintInvalidation(scrollbar.get());
-
+    if (invalidate) {
+        m_scrollableArea->box().invalidateDisplayItemClient(*scrollbar);
+        scrollbar->invalidate();
+    }
     if (!scrollbar->isCustomScrollbar())
         m_scrollableArea->willRemoveScrollbar(scrollbar.get(), orientation);