Fold alpha to the inner savelayer in savelayer-savelayer-restore patterns

src/core/SkRecordPattern.h

 #ifndef SkRecordPattern_DEFINED
 #define SkRecordPattern_DEFINED
 
 #include "SkTLogic.h"
 
 namespace SkRecords {
 
 // First, some matchers.  These match a single command in the SkRecord,
 // and may hang onto some data from it.  If so, you can get the data by calling .get().
 
@@ skipping 114 matching lines @@
         }
         return false;
     }
 
     // Once either match or search has succeeded, access the stored data of the first, second,
     // or third matcher in this pattern.  Add as needed for longer patterns.
     // T is checked statically at compile time; no casting is involved.  It's just an API wart.
     template <typename T> T* first()  { return fHead.get(); }
     template <typename T> T* second() { return fTail.fHead.get(); }
     template <typename T> T* third()  { return fTail.fTail.fHead.get(); }
+    template <typename T> T* fourth()  { return fTail.fTail.fTail.fHead.get(); }
 
 private:
     // If head isn't a Star, try to match at i once.
     template <typename T>
     unsigned matchHead(T*, SkRecord* record, unsigned i) {
         if (i < record->count()) {
             if (record->mutate<bool>(i, fHead)) {
                 return i+1;
             }
         }
@@ skipping 30 matching lines @@
 // All types A, B, C, ... are Matchers.
 template <typename A>
 struct Pattern1 : Cons<A, Nil> {};
 
 template <typename A, typename B>
 struct Pattern2 : Cons<A, Pattern1<B> > {};
 
 template <typename A, typename B, typename C>
 struct Pattern3 : Cons<A, Pattern2<B, C> > {};
 
+template <typename A, typename B, typename C, typename D>
+struct Pattern4 : Cons<A, Pattern3<B, C, D> > {};
+
+template <typename A, typename B, typename C, typename D, typename E>
+struct Pattern5 : Cons<A, Pattern4<B, C, D, E> > {};
+
+template <typename A, typename B, typename C, typename D, typename E, typename F>
+struct Pattern6 : Cons<A, Pattern5<B, C, D, E, F> > {};
+
+template <typename A, typename B, typename C, typename D, typename E, typename F, typename G>
+struct Pattern7 : Cons<A, Pattern6<B, C, D, E, F, G> > {};
+
 }  // namespace SkRecords
 
 #endif//SkRecordPattern_DEFINED