Ensure VM's heap is accounted correctly.

The meminfo dumping assumes that dalvik heap is created using ashmem and has a
prefix of "dalvik-". Ensure ART's anonymous mmaps fit this pattern. Tidy up
anonymous mmaps so naming is more consistent.

Change-Id: I9c62a9d1da21da6a048effb0399a1f85865cb12d
diff --git a/src/heap.cc b/src/heap.cc
index f7abe0a..c8df031 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -284,10 +284,10 @@
 
   // Default mark stack size in bytes.
   static const size_t default_mark_stack_size = 64 * KB;
-  mark_stack_.reset(ObjectStack::Create("dalvik-mark-stack", default_mark_stack_size));
-  allocation_stack_.reset(ObjectStack::Create("dalvik-allocation-stack",
+  mark_stack_.reset(ObjectStack::Create("mark stack", default_mark_stack_size));
+  allocation_stack_.reset(ObjectStack::Create("allocation stack",
                                               max_allocation_stack_size_));
-  live_stack_.reset(ObjectStack::Create("dalvik-live-stack",
+  live_stack_.reset(ObjectStack::Create("live stack",
                                       max_allocation_stack_size_));
 
   // It's still too early to take a lock because there are no threads yet, but we can create locks