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

third_party/WebKit/Source/platform/graphics/paint/DisplayItem.h

Index: third_party/WebKit/Source/platform/graphics/paint/DisplayItem.h
diff --git a/third_party/WebKit/Source/platform/graphics/paint/DisplayItem.h b/third_party/WebKit/Source/platform/graphics/paint/DisplayItem.h
index d46c21841377d670912c9999e3c1a84454f444b7..066928e45db84bd9abc1c627f49e9b741edc44e2 100644
--- a/third_party/WebKit/Source/platform/graphics/paint/DisplayItem.h
+++ b/third_party/WebKit/Source/platform/graphics/paint/DisplayItem.h
@@ -182,6 +182,10 @@
     kEndTransform,
     kBeginClipPath,
     kEndClipPath,
+
+    kSubsequence,
+    kEndSubsequence,
+
     kUninitializedType,
     kTypeLast = kUninitializedType
   };
@@ -310,7 +314,9 @@
 
   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);
   }