Implement committed physical memory stats for Linux.

src/heap.h

Index: src/heap.h
diff --git a/src/heap.h b/src/heap.h
index 46ec6cf660f841ffde53d4a47d1298c4ed217afa..c7597923441d2da78918dc3f795b276a4bdb6175 100644
--- a/src/heap.h
+++ b/src/heap.h
@@ -486,6 +486,9 @@ class Heap {
   // Returns the amount of executable memory currently committed for the heap.
   intptr_t CommittedMemoryExecutable();
 
+  // Returns the amount of phyical memory currently committed for the heap.
+  size_t CommittedPhysicalMemory();

[Yang, 2012/09/24 14:05:35]

Any reason why this is a size_t while the rest are intptr_t?

[alph-g, 2012/09/24 14:09:59]

I have no idea why the rest are intptr_t. The returned value is obviously
size_t, it cannot be negative.

[Michael Starzinger, 2012/09/27 09:46:16]

Yeah, the others should be size_t as well I guess. But that is for another day
to cleanup.

+
   // Returns the available bytes in space w/o growing.
   // Heap doesn't guarantee that it can allocate an object that requires
   // all available bytes. Check MaxHeapObjectSize() instead.