[Slimming Paint] Add *FilterDisplayItem type for slimming paint

Source/core/paint/FilterPainter.cpp

Index: Source/core/paint/FilterPainter.cpp
diff --git a/Source/core/paint/FilterPainter.cpp b/Source/core/paint/FilterPainter.cpp
index 9fe1e9483320a57f3a1cfcceab9c7b82676bfcc1..9f82642290490af86ce93167d5afe5eecaed07c8 100644
--- a/Source/core/paint/FilterPainter.cpp
+++ b/Source/core/paint/FilterPainter.cpp
@@ -8,16 +8,52 @@
 #include "core/paint/LayerPainter.h"
 #include "core/rendering/FilterEffectRenderer.h"
 #include "core/rendering/RenderLayer.h"
+#include "core/rendering/RenderView.h"
+#include "platform/RuntimeEnabledFeatures.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/filters/FilterEffect.h"
 #include "platform/graphics/filters/SkiaImageFilterBuilder.h"
 
 namespace blink {
 
+void BeginFilterDisplayItem::replay(GraphicsContext* context)
+{
+    context->save();
+    FloatRect boundaries = mapImageFilterRect(m_imageFilter.get(), m_bounds);
+    context->translate(m_bounds.x().toFloat(), m_bounds.y().toFloat());
+    boundaries.move(-m_bounds.x().toFloat(), -m_bounds.y().toFloat());
+    context->beginLayer(1, CompositeSourceOver, &boundaries, ColorFilterNone, m_imageFilter.get());
+    context->translate(-m_bounds.x().toFloat(), -m_bounds.y().toFloat());
+}
+
+#ifndef NDEBUG
+WTF::String BeginFilterDisplayItem::asDebugString() const
+{
+    return String::format("{%s, type: \"%s\", filter bounds: [%f,%f,%f,%f]}",
+        rendererDebugString(renderer()).utf8().data(), typeAsDebugString(type()).utf8().data(),
+        m_bounds.x().toFloat(), m_bounds.y().toFloat(), m_bounds.width().toFloat(), m_bounds.height().toFloat());
+}
+#endif
+
+void EndFilterDisplayItem::replay(GraphicsContext* context)
+{
+    context->endLayer();
+    context->restore();
+}
+
+#ifndef NDEBUG
+WTF::String EndFilterDisplayItem::asDebugString() const
+{
+    return String::format("{%s, type: \"%s\"}",
+        rendererDebugString(renderer()).utf8().data(), typeAsDebugString(type()).utf8().data());
+}
+#endif
+
 FilterPainter::FilterPainter(RenderLayer& renderLayer, GraphicsContext* context, const LayoutPoint& offsetFromRoot, const ClipRect& clipRect, LayerPaintingInfo& paintingInfo, PaintLayerFlags paintFlags,
     LayoutRect& rootRelativeBounds, bool& rootRelativeBoundsComputed)
     : m_filterInProgress(false)
     , m_context(context)
+    , m_renderer(renderLayer.renderer())
 {
     if (!renderLayer.filterRenderer() || !renderLayer.paintsWithFilters())
         return;
@@ -50,20 +86,26 @@ FilterPainter::FilterPainter(RenderLayer& renderLayer, GraphicsContext* context,
             LayerPainter::applyRoundedRectClips(renderLayer, paintingInfo, context, paintFlags, *m_clipRecorder);
     }
 
-    context->save();
-    FloatRect boundaries = mapImageFilterRect(imageFilter.get(), rootRelativeBounds);
-    context->translate(rootRelativeBounds.x().toFloat(), rootRelativeBounds.y().toFloat());
-    boundaries.move(-rootRelativeBounds.x().toFloat(), -rootRelativeBounds.y().toFloat());
-    context->beginLayer(1, CompositeSourceOver, &boundaries, ColorFilterNone, imageFilter.get());
-    context->translate(-rootRelativeBounds.x().toFloat(), -rootRelativeBounds.y().toFloat());
+    OwnPtr<BeginFilterDisplayItem> filterDisplayItem = adoptPtr(new BeginFilterDisplayItem(m_renderer, DisplayItem::BeginFilter, imageFilter, rootRelativeBounds));
+    if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
+        renderLayer.renderer()->view()->viewDisplayList().add(filterDisplayItem.release());
+    } else {
+        filterDisplayItem->replay(context);
+    }
+
     m_filterInProgress = true;
 }
 
 FilterPainter::~FilterPainter()
 {
-    if (m_filterInProgress) {
-        m_context->endLayer();
-        m_context->restore();
+    if (!m_filterInProgress)
+        return;
+
+    OwnPtr<EndFilterDisplayItem> endFilterDisplayItem = adoptPtr(new EndFilterDisplayItem(m_renderer));
+    if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
+        m_renderer->view()->viewDisplayList().add(endFilterDisplayItem.release());
+    } else {
+        endFilterDisplayItem->replay(m_context);
     }
 }