New display item caching

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 "config.h"
 #include "core/paint/BlockPainter.h"
 
 #include "core/editing/Caret.h"
 #include "core/editing/FrameSelection.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/page/Page.h"
 #include "core/paint/BoxClipper.h"
 #include "core/paint/BoxPainter.h"
 #include "core/paint/GraphicsContextAnnotator.h"
 #include "core/paint/InlinePainter.h"
 #include "core/paint/LineBoxListPainter.h"
 #include "core/paint/RenderDrawingRecorder.h"
 #include "core/paint/ScrollableAreaPainter.h"
+#include "core/paint/SubtreeInfoRecorder.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderBlock.h"
 #include "core/rendering/RenderFlexibleBox.h"
 #include "core/rendering/RenderInline.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderView.h"
 #include "platform/geometry/LayoutPoint.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/graphics/GraphicsContextStateSaver.h"
 
 namespace blink {
 
 void BlockPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     PaintInfo localPaintInfo(paintInfo);
+    SubtreeInfoRecorder subtreeInfoRecorder(paintInfo.context, m_renderBlock, localPaintInfo.phase);
 
     ANNOTATE_GRAPHICS_CONTEXT(localPaintInfo, &m_renderBlock);
 
     LayoutPoint adjustedPaintOffset = paintOffset + m_renderBlock.location();
 
     PaintPhase originalPhase = localPaintInfo.phase;
 
     // Check if we need to do anything at all.
     // FIXME: Could eliminate the isDocumentElement() check if we fix background painting so that the RenderView
     // paints the root's background.
     if (!m_renderBlock.isDocumentElement()) {
         LayoutRect overflowBox = overflowRectForPaintRejection();
         m_renderBlock.flipForWritingMode(overflowBox);
         overflowBox.moveBy(adjustedPaintOffset);
         if (!overflowBox.intersects(localPaintInfo.rect))
             return;
     }
 
+    subtreeInfoRecorder.begin();
+
     // There are some cases where not all clipped visual overflow is accounted for.
     // FIXME: reduce the number of such cases.
     ContentsClipBehavior contentsClipBehavior = ForceContentsClip;
     if (m_renderBlock.hasOverflowClip() && !m_renderBlock.hasControlClip() && !(m_renderBlock.shouldPaintSelectionGaps() && originalPhase == PaintPhaseForeground) && !hasCaret())
         contentsClipBehavior = SkipContentsClipIfPossible;
 
     if (localPaintInfo.phase == PaintPhaseOutline) {
         localPaintInfo.phase = PaintPhaseChildOutlines;
     } else if (localPaintInfo.phase == PaintPhaseChildBlockBackground) {
         localPaintInfo.phase = PaintPhaseBlockBackground;
@@ skipping 426 matching lines @@
         RenderBlock* block = flow->containingBlock();
         for ( ; block && block != &m_renderBlock; block = block->containingBlock())
             accumulatedPaintOffset.moveBy(block->location());
         ASSERT(block);
         InlinePainter(*flow).paintOutline(info, accumulatedPaintOffset);
     }
 }
 
 
 } // namespace blink