Enable fast/images with slimming paint

Source/core/paint/TransparencyDisplayItem.h

Index: Source/core/paint/TransparencyDisplayItem.h
diff --git a/Source/core/paint/TransparencyDisplayItem.h b/Source/core/paint/TransparencyDisplayItem.h
index 290d916f0d37c830bc8643a72329522ab380c8fd..30ad744259011975bf3149e78c999f7c1a9263fd 100644
--- a/Source/core/paint/TransparencyDisplayItem.h
+++ b/Source/core/paint/TransparencyDisplayItem.h
@@ -11,11 +11,12 @@
 
 namespace blink {
 
+// FIXME: Move this file to TransparencyRecorder
+
 class BeginTransparencyDisplayItem : public DisplayItem {
 public:
-    BeginTransparencyDisplayItem(const RenderObject* renderer, Type type, const LayoutRect& clipRect, const WebBlendMode& blendMode, const float opacity)
+    BeginTransparencyDisplayItem(const RenderObject* renderer, Type type, const WebBlendMode& blendMode, const float opacity)
         : DisplayItem(renderer, type)
-        , m_clipRect(clipRect)
         , m_blendMode(blendMode)
         , m_opacity(opacity) { }
     virtual void replay(GraphicsContext*) override;
@@ -27,7 +28,6 @@ private:
 
     bool hasBlendMode() const { return m_blendMode != WebBlendModeNormal; }
 
-    const LayoutRect m_clipRect;
     const WebBlendMode m_blendMode;
     const float m_opacity;
 };
@@ -44,6 +44,18 @@ private:
 #endif
 };
 
+class TransparencyRecorder {
+public:
+    explicit TransparencyRecorder(GraphicsContext*, const RenderObject*, DisplayItem::Type, const WebBlendMode&, const float opacity);
+
+    ~TransparencyRecorder();
+
+private:
+    const RenderObject* m_renderer;
+    const DisplayItem::Type m_type;
+    GraphicsContext* m_graphicsContext;
+};
+
 } // namespace blink
 
 #endif // TransparencyDisplayItem_h