change drawPicture in SkRecord to just ref the picture

src/core/SkRecord.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkRecord_DEFINED
 #define SkRecord_DEFINED
 
@@ skipping 46 matching lines @@
     template <typename R, typename F>
     R mutate(unsigned i, F& f) {
         SkASSERT(i < this->count());
         return fRecords[i].mutate<R>(fTypes[i], f);
     }
     // TODO: It'd be nice to infer R from F for visit and mutate if we ever get std::result_of.
 
     // Allocate contiguous space for count Ts, to be freed when the SkRecord is destroyed.
     // Here T can be any class, not just those from SkRecords.  Throws on failure.
     template <typename T>
-    T* alloc(unsigned count = 1) {
+    T* alloc(size_t count = 1) {
         return (T*)fAlloc.allocThrow(sizeof(T) * count);
     }
 
     // Add a new command of type T to the end of this SkRecord.
     // You are expected to placement new an object of type T onto this pointer.
     template <typename T>
     T* append() {
         if (fCount == fReserved) {
             fReserved = SkTMax(kFirstReserveCount, fReserved*2);
             fRecords.realloc(fReserved);
@@ skipping 147 matching lines @@
     SkChunkAlloc fAlloc;
     SkAutoTMalloc<Record> fRecords;
     SkAutoTMalloc<Type8> fTypes;
     // fCount and fReserved measure both fRecords and fTypes, which always grow in lock step.
     unsigned fCount;
     unsigned fReserved;
     const unsigned kFirstReserveCount;
 };
 
 #endif//SkRecord_DEFINED