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/mem_map.cc b/src/mem_map.cc
index 32f0530..a7fb5c4 100644
--- a/src/mem_map.cc
+++ b/src/mem_map.cc
@@ -73,7 +73,11 @@
   CheckMapRequest(addr, page_aligned_byte_count);
 
 #ifdef USE_ASHMEM
-  ScopedFd fd(ashmem_create_region(name, page_aligned_byte_count));
+  // android_os_Debug.cpp read_mapinfo assumes all ashmem regions associated with the VM are
+  // prefixed "dalvik-".
+  std::string debug_friendly_name("dalvik-");
+  debug_friendly_name += name;
+  ScopedFd fd(ashmem_create_region(debug_friendly_name.c_str(), page_aligned_byte_count));
   int flags = MAP_PRIVATE;
   if (fd.get() == -1) {
     PLOG(ERROR) << "ashmem_create_region failed (" << name << ")";