Enable fast/images with slimming paint

Source/core/paint/BoxClipper.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/BoxClipper.h"
 
 #include "core/paint/ClipRecorder.h"
 #include "core/paint/ViewDisplayList.h"
 #include "core/rendering/PaintInfo.h"
@@ skipping 45 matching lines @@
         m_paintInfo.phase = PaintPhaseChildOutlines;
     } else if (m_paintInfo.phase == PaintPhaseChildBlockBackground) {
         m_paintInfo.phase = PaintPhaseBlockBackground;
         // FIXME: refactor to not call paintObject from within a clipping helper.
         m_box.paintObject(m_paintInfo, m_accumulatedOffset);
         m_paintInfo.phase = PaintPhaseChildBlockBackgrounds;
     }
 
     DisplayItem::Type clipType = DisplayItem::ClipBoxForeground;
     if (RuntimeEnabledFeatures::slimmingPaintEnabled()) {
-        switch (m_paintInfo.phase) {
-        case PaintPhaseChildBlockBackgrounds:
-            clipType = DisplayItem::ClipBoxChildBlockBackgrounds;
-            break;
-        case PaintPhaseFloat:
-            clipType = DisplayItem::ClipBoxFloat;
-            break;
-        case PaintPhaseForeground:
-            clipType = DisplayItem::ClipBoxChildBlockBackgrounds;
-            break;
-        case PaintPhaseChildOutlines:
-            clipType = DisplayItem::ClipBoxChildOutlines;
-            break;
-        case PaintPhaseSelection:
-            clipType = DisplayItem::ClipBoxSelection;
-            break;
-        case PaintPhaseCollapsedTableBorders:
-            clipType = DisplayItem::ClipBoxCollapsedTableBorders;
-            break;
-        case PaintPhaseTextClip:
-            clipType = DisplayItem::ClipBoxTextClip;
-            break;
-        case PaintPhaseClippingMask:
-            clipType = DisplayItem::ClipBoxClippingMask;
-            break;
-        case PaintPhaseChildBlockBackground:
-        case PaintPhaseOutline:
-        case PaintPhaseBlockBackground:
-        case PaintPhaseSelfOutline:
-        case PaintPhaseMask:
-            ASSERT_NOT_REACHED();
-        }
+        clipType = DisplayItem::paintPhaseToClipType(m_paintInfo.phase);
     }
 
     OwnPtr<ClipDisplayItem> clipDisplayItem = adoptPtr(new ClipDisplayItem(&m_box, clipType, pixelSnappedIntRect(clipRect)));
     if (hasBorderRadius)
         clipDisplayItem->roundedRectClips().append(clipRoundedRect);
 
     if (RuntimeEnabledFeatures::slimmingPaintEnabled())
         m_box.view()->viewDisplayList().add(clipDisplayItem.release());
     else
         clipDisplayItem->replay(paintInfo.context);
@@ skipping 20 matching lines @@
     if (m_originalPhase == PaintPhaseOutline) {
         m_paintInfo.phase = PaintPhaseSelfOutline;
         m_box.paintObject(m_paintInfo, m_accumulatedOffset);
         m_paintInfo.phase = m_originalPhase;
     } else if (m_originalPhase == PaintPhaseChildBlockBackground) {
         m_paintInfo.phase = m_originalPhase;
     }
 }
 
 } // namespace blink