Enable fast/images with slimming paint

Source/core/paint/ViewDisplayList.h

 // 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.
 
 #ifndef ViewDisplayList_h
 #define ViewDisplayList_h
 
 #include "core/rendering/PaintPhase.h"
 #include "wtf/HashSet.h"
 #include "wtf/PassOwnPtr.h"
@@ skipping 31 matching lines @@
         ClipLayerFragmentChildOutline = 20,
         ClipLayerFragmentOutline = 21,
         ClipLayerFragmentMask = 22,
         ClipLayerFragmentClippingMask = 23,
         ClipLayerFragmentParent = 24,
         ClipLayerFragmentSelection = 25,
         ClipLayerFragmentChildBlockBackgrounds = 26,
         EndClip = 27,
         BeginFilter = 28,
         EndFilter = 29,
-        BeginTransparency = 30,

[chrishtr, 2014/11/25 00:29:58]

Let's get rid of the numbers that are not necessary here.

-        EndTransparency = 31,
-        ClipBoxChildBlockBackgrounds = 32,
-        ClipBoxFloat = 33,
-        ClipBoxForeground = 34,
-        ClipBoxChildOutlines = 35,
-        ClipBoxSelection = 36,
-        ClipBoxCollapsedTableBorders = 37,
-        ClipBoxTextClip = 38,
-        ClipBoxClippingMask = 39,
-        BeginTransform = 40,
-        EndTransform = 41
+        TransparencyClip = 30,
+        BeginTransparency = 31,
+        EndTransparency = 32,
+        ClipBoxChildBlockBackgrounds = 33,
+        ClipBoxFloat = 34,
+        ClipBoxForeground = 35,
+        ClipBoxChildOutlines = 36,
+        ClipBoxSelection = 37,
+        ClipBoxCollapsedTableBorders = 38,
+        ClipBoxTextClip = 39,
+        ClipBoxClippingMask = 40,
+        BeginTransform = 41,
+        EndTransform = 42
     };
 
     virtual ~DisplayItem() { }
 
     virtual void replay(GraphicsContext*) = 0;
 
     const RenderObject* renderer() const { return m_id.renderer; }
     Type type() const { return m_id.type; }
     bool idsEqual(const DisplayItem& other) const { return m_id.renderer == other.m_id.renderer && m_id.type == other.m_id.type; }
 
+    static Type paintPhaseToClipType(PaintPhase);
+
 #ifndef NDEBUG
     static WTF::String typeAsDebugString(DisplayItem::Type);
     static WTF::String rendererDebugString(const RenderObject*);
     virtual WTF::String asDebugString() const;
 #endif
 
 protected:
     DisplayItem(const RenderObject* renderer, Type type)
         : m_id(renderer, type)
     { }
@@ skipping 31 matching lines @@
 
     PaintList m_paintList;
     HashSet<const RenderObject*> m_paintListRenderers;
     HashSet<const RenderObject*> m_invalidated;
     PaintList m_newPaints;
 };
 
 } // namespace blink
 
 #endif // ViewDisplayList_h