Adds support for collecting statistics about code and its metadata.

src/heap/heap.h

 // Copyright 2012 the V8 project 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 V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 1150 matching lines @@
   // Objects are being grouped into buckets that roughly resemble existing
   // instance types.
   size_t ObjectCountAtLastGC(size_t index);
   size_t ObjectSizeAtLastGC(size_t index);
 
   // Retrieves names of buckets used by object statistics tracking.
   bool GetObjectTypeName(size_t index, const char** object_type,
                          const char** object_sub_type);
 
   // ===========================================================================
+  // Code statistics. ==========================================================
+  // ===========================================================================
+
+  // Collect code (Code and BytecodeArray objects) statistics.
+  void CollectCodeStatistics();
+
+  // ===========================================================================
   // GC statistics. ============================================================
   // ===========================================================================
 
   // Returns the maximum amount of memory reserved for the heap.
   intptr_t MaxReserved() {
     return 2 * max_semi_space_size_ + max_old_generation_size_;
   }
   int MaxSemiSpaceSize() { return max_semi_space_size_; }
   int InitialSemiSpaceSize() { return initial_semispace_size_; }
   intptr_t MaxOldGenerationSize() { return max_old_generation_size_; }
@@ skipping 1466 matching lines @@
   friend class LargeObjectSpace;
   friend class NewSpace;
   friend class PagedSpace;
   DISALLOW_COPY_AND_ASSIGN(AllocationObserver);
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_HEAP_HEAP_H_