Implement SkPicture::bytesUsed() for SkRecord backend

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 92 matching lines @@
     T* replace(unsigned i, const SkRecords::Adopted<Existing>& proofOfAdoption) {
         SkASSERT(i < this->count());
 
         SkASSERT(Existing::kType == fTypes[i]);
         SkASSERT(proofOfAdoption == fRecords[i].ptr<Existing>());
 
         fTypes[i] = T::kType;
         return fRecords[i].set(this->allocCommand<T>());
     }
 
+    size_t bytesUsed() const { return fAlloc.totalCapacity() +
+                                      fReserved * (sizeof(Record) + sizeof(Type8)) +
+                                      sizeof(SkRecord); }
+
 private:
     // Implementation notes!
     //
     // Logically an SkRecord is structured as an array of pointers into a big chunk of memory where
     // records representing each canvas draw call are stored:
     //
     // fRecords:  [*][*][*]...
     //             |  |  |
     //             |  |  |
     //             |  |  +---------------------------------------+
@@ skipping 102 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