Revert of Remove begin/end subseq. display items, and store on PaintController instead.

third_party/WebKit/Source/platform/graphics/paint/DisplayItem.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 DisplayItem_h
 #define DisplayItem_h
 
 #include "platform/PlatformExport.h"
 #include "platform/graphics/ContiguousContainer.h"
 #include "platform/graphics/paint/DisplayItemClient.h"
@@ skipping 164 matching lines @@
         kEndTransform3DFirst + kTransform3DLast - kTransform3DFirst,
 
     kBeginFilter,
     kEndFilter,
     kBeginCompositing,
     kEndCompositing,
     kBeginTransform,
     kEndTransform,
     kBeginClipPath,
     kEndClipPath,
+
+    kSubsequence,
+    kEndSubsequence,
+
     kUninitializedType,
     kTypeLast = kUninitializedType
   };
 
   static_assert(kTableCollapsedBorderBase >= kTableCollapsedBorderUnalignedBase,
                 "TableCollapsedBorder types overlap with other types");
   static_assert((kTableCollapsedBorderBase & 0xf) == 0,
                 "The lowest 4 bits of TableCollapsedBorderBase should be zero");
   // Bits or'ed onto TableCollapsedBorderBase to generate a real table collapsed
   // border type.
@@ skipping 108 matching lines @@
   DEFINE_PAINT_PHASE_CONVERSION_METHOD(ClipColumnBounds)
 
   DEFINE_PAIRED_CATEGORY_METHODS(FloatClip, floatClip)
   DEFINE_PAINT_PHASE_CONVERSION_METHOD(FloatClip)
 
   DEFINE_PAIRED_CATEGORY_METHODS(Scroll, scroll)
   DEFINE_PAINT_PHASE_CONVERSION_METHOD(Scroll)
 
   DEFINE_PAIRED_CATEGORY_METHODS(Transform3D, transform3D)
 
-  static bool isCacheableType(Type type) { return isDrawingType(type); }
+  static bool isCacheableType(Type type) {
+    return isDrawingType(type) || type == kSubsequence;
+  }
   bool isCacheable() const {
     return !skippedCache() && isCacheableType(m_type);
   }
 
   virtual bool isBegin() const { return false; }
   virtual bool isEnd() const { return false; }
 
 #if DCHECK_IS_ON()
   virtual bool isEndAndPairedWith(DisplayItem::Type otherType) const {
     return false;
@@ skipping 80 matching lines @@
   bool isEndAndPairedWith(DisplayItem::Type otherType) const override = 0;
 #endif
 
  private:
   bool isEnd() const final { return true; }
 };
 
 }  // namespace blink
 
 #endif  // DisplayItem_h