(WIP) Invalidation during painting (for synchronized painting)

third_party/WebKit/Source/core/paint/BlockPainter.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 "core/paint/BlockPainter.h"
 
 #include "core/editing/DragCaretController.h"
 #include "core/editing/FrameSelection.h"
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutBlockFlow.h"
@@ skipping 110 matching lines @@
 
     LayoutPoint childPoint = paintOffset;
     if (inlineBox.parent()->lineLayoutItem().style()->isFlippedBlocksWritingMode()) // Faster than calling containingBlock().
         childPoint = LineLayoutAPIShim::layoutObjectFrom(inlineBox.lineLayoutItem())->containingBlock()->flipForWritingModeForChild(toLayoutBox(LineLayoutAPIShim::layoutObjectFrom(inlineBox.lineLayoutItem())), childPoint);
 
     ObjectPainter(*LineLayoutAPIShim::constLayoutObjectFrom(inlineBox.lineLayoutItem())).paintAsPseudoStackingContext(paintInfo, childPoint);
 }
 
 void BlockPainter::paintObject(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
-    if (RuntimeEnabledFeatures::slimmingPaintOffsetCachingEnabled() && m_layoutBlock.childrenInline() && !paintInfo.context.paintController().skippingCache()) {
-        if (m_layoutBlock.paintOffsetChanged(paintOffset)) {
-            LineBoxListPainter(m_layoutBlock.lineBoxes()).invalidateLineBoxPaintOffsets(paintInfo);
-            paintInfo.context.paintController().invalidatePaintOffset(m_layoutBlock);
-        }
-        // Set previousPaintOffset here in case that m_layoutBlock paints nothing and no
-        // LayoutObjectDrawingRecorder updates its previousPaintOffset.
-        // TODO(wangxianzhu): Integrate paint offset checking into new paint invalidation.
-        m_layoutBlock.mutableForPainting().setPreviousPaintOffset(paintOffset);
-    }
-
     const PaintPhase paintPhase = paintInfo.phase;
 
     if (shouldPaintSelfBlockBackground(paintPhase)) {
         if (m_layoutBlock.style()->visibility() == VISIBLE && m_layoutBlock.hasBoxDecorationBackground())
             m_layoutBlock.paintBoxDecorationBackground(paintInfo, paintOffset);
         // We're done. We don't bother painting any children.
         if (paintPhase == PaintPhaseSelfBlockBackgroundOnly)
             return;
     }
 
@@ skipping 36 matching lines @@
 
         if (paintPhase == PaintPhaseFloat || paintPhase == PaintPhaseSelection || paintPhase == PaintPhaseTextClip)
             m_layoutBlock.paintFloats(contentsPaintInfo, paintOffset);
     }
 
     if (shouldPaintSelfOutline(paintPhase))
         ObjectPainter(m_layoutBlock).paintOutline(paintInfo, paintOffset);
 
     // If the caret's node's layout object's containing block is this block, and the paint action is PaintPhaseForeground,
     // then paint the caret.
-    if (paintPhase == PaintPhaseForeground && m_layoutBlock.hasCaret() && !LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(paintInfo.context, m_layoutBlock, DisplayItem::Caret, paintOffset)) {
+    if (paintPhase == PaintPhaseForeground && m_layoutBlock.hasCaret() && !LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(paintInfo.context, m_layoutBlock, DisplayItem::Caret)) {
         LayoutRect bounds = m_layoutBlock.visualOverflowRect();
         bounds.moveBy(paintOffset);
         LayoutObjectDrawingRecorder recorder(paintInfo.context, m_layoutBlock, DisplayItem::Caret, bounds, paintOffset);
         paintCarets(paintInfo, paintOffset);
     }
 }
 
 void BlockPainter::paintCarets(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     LocalFrame* frame = m_layoutBlock.frame();
@@ skipping 42 matching lines @@
             ObjectPainter(m_layoutBlock).paintInlineChildrenOutlines(paintInfo, paintOffset);
         else
             LineBoxListPainter(m_layoutBlock.lineBoxes()).paint(m_layoutBlock, paintInfo, paintOffset);
     } else {
         PaintInfo paintInfoForDescendants = paintInfo.forDescendants();
         m_layoutBlock.paintChildren(paintInfoForDescendants, paintOffset);
     }
 }
 
 } // namespace blink