Add native memory accounting through custom allocator.

Added a custom allocator that lets you pass in a special tag which
specifices where the allocation came from. This is used when
dumping. The performance overhead is low since each allocation only
does a atomic add/sub for each allocation/free.

The measurements are dumped to traces.txt during SIGQUIT.

Example output:
I/art     (27274): AllocatorTagHeap active=120 max=120 total=168
I/art     (27274): AllocatorTagMonitorList active=1572 max=6240 total=11724
I/art     (27274): AllocatorTagClassTable active=185208 max=185208 total=268608
I/art     (27274): AllocatorTagInternTable active=430368 max=430368 total=436080
I/art     (27274): AllocatorTagMaps active=5616 max=6168 total=34392
I/art     (27274): AllocatorTagLOS active=1024 max=1536 total=2044
I/art     (27274): AllocatorTagSafeMap active=0 max=51936 total=533688
I/art     (27274): AllocatorTagLOSMaps active=144 max=1248 total=5760
I/art     (27274): AllocatorTagReferenceTable active=10944 max=11840 total=19136
I/art     (27274): AllocatorTagHeapBitmap active=32 max=40 total=56
I/art     (27274): AllocatorTagHeapBitmapLOS active=8 max=8 total=8
I/art     (27274): AllocatorTagVerifier active=0 max=18844 total=1073156
I/art     (27274): AllocatorTagModUnionCardSet active=5300 max=5920 total=56020
I/art     (27274): AllocatorTagModUnionReferenceArray active=24864 max=24864 total=24864
I/art     (27274): AllocatorTagJNILibrarires active=320 max=320 total=320
I/art     (27274): AllocatorTagOatFile active=1400 max=1400 total=5852

Change-Id: Ibb470ef2e9c9a24563bb46422d46a55799704d82

(cherry picked from commit 5369c40f75fdcb1be7a7c06db212ce965c83a164)
diff --git a/runtime/safe_map.h b/runtime/safe_map.h
index f7e238c..f9d81dc 100644
--- a/runtime/safe_map.h
+++ b/runtime/safe_map.h
@@ -20,6 +20,7 @@
 #include <map>
 #include <memory>
 
+#include "base/allocator.h"
 #include "base/logging.h"
 
 namespace art {
@@ -27,7 +28,7 @@
 // Equivalent to std::map, but without operator[] and its bug-prone semantics (in particular,
 // the implicit insertion of a default-constructed value on failed lookups).
 template <typename K, typename V, typename Comparator = std::less<K>,
-          typename Allocator = std::allocator<std::pair<const K, V>>>
+          typename Allocator = TrackingAllocator<std::pair<const K, V>, kAllocatorTagSafeMap>>
 class SafeMap {
  private:
   typedef SafeMap<K, V, Comparator, Allocator> Self;
@@ -130,6 +131,11 @@
   return !(lhs == rhs);
 }
 
+template<class Key, class T, AllocatorTag kTag, class Compare = std::less<Key>>
+class AllocationTrackingSafeMap : public SafeMap<
+    Key, T, Compare, TrackingAllocator<std::pair<Key, T>, kTag>> {
+};
+
 }  // namespace art
 
 #endif  // ART_RUNTIME_SAFE_MAP_H_