Provide more accurate results about used heap size via GetHeapStatistics.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index c37ced39399830e48d4fd59f1ae420f1ec3c0fb4..fd0e9b5c33e6da0ad3ea61346bef37ba9589bdc5 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -275,8 +275,12 @@ class Heap : public AllStatic {
   // Returns the maximum object size in paged space.
   static inline int MaxObjectSizeInPagedSpace();
 
-  // Returns of size of all objects residing in the heap.
+  // Returns size of all objects residing in the heap.
   static intptr_t SizeOfObjects();
+  // Does the same as the previous function, but more precisely,

[Mads Ager (chromium), 2010/11/12 11:11:27]

Hmm, this looks strange. Computing the same but getting a different result.

That indicates to me that the SizeOfObjects method is either incorrectly named
or should be fixed.

I wonder if the difference here is only due to the free-list being excluded in
your implementation. If that is the case we should fix the original method to
exclude the size of the memory in the free list which we should have available
directly somewhere.

+  // by iterating heap contents. The resulting number is usually
+  // ~10% lower.
+  static intptr_t SizeOfObjectsSlow();
 
   // Return the starting address and a mask for the new space.  And-masking an
   // address with the mask will result in the start address of the new space