Add allocation tracking allocators to ROSAlloc

Used to monitor native memory usage, results are approximately
12-100KB memory per app.

Change-Id: If5a46cd8d543851948a8cb69487f3044965b44ce
diff --git a/runtime/base/allocator.h b/runtime/base/allocator.h
index a7adb02..2c3e966 100644
--- a/runtime/base/allocator.h
+++ b/runtime/base/allocator.h
@@ -66,6 +66,7 @@
   kAllocatorTagCompileTimeClassPath,
   kAllocatorTagOatFile,
   kAllocatorTagDexFileVerifier,
+  kAllocatorTagRosAlloc,
   kAllocatorTagCount,  // Must always be last element.
 };
 std::ostream& operator<<(std::ostream& os, const AllocatorTag& tag);
@@ -149,6 +150,10 @@
     Key, T, Compare, TrackingAllocator<std::pair<Key, T>, kTag>> {
 };
 
+template<class Key, AllocatorTag kTag, class Compare = std::less<Key>>
+class AllocationTrackingSet : public std::set<Key, Compare, TrackingAllocator<Key, kTag>> {
+};
+
 }  // namespace art
 
 #endif  // ART_RUNTIME_BASE_ALLOCATOR_H_