Separate Malloc and MemMap ArenaPools

Make ArenaPool an abstract base class and leave MallocArenaPool
implementation with it.  This enables arena_allocator to be free
of MemMap, Mutex, etc., in preparation to move the remaining collections
out of runtime/base to libartbase/base.

Bug: 22322814
Test: make -j 50 test-art-host
      build and boot

Change-Id: Ief84dcbfb749165d9bc82000c6b8f96f93052422
diff --git a/compiler/utils/assembler_thumb_test.cc b/compiler/utils/assembler_thumb_test.cc
index 655d17d..053e202 100644
--- a/compiler/utils/assembler_thumb_test.cc
+++ b/compiler/utils/assembler_thumb_test.cc
@@ -27,6 +27,7 @@
 #include "utils/arm/jni_macro_assembler_arm_vixl.h"
 
 #include "base/hex_dump.h"
+#include "base/malloc_arena_pool.h"
 #include "common_runtime_test.h"
 
 namespace art {
@@ -169,7 +170,7 @@
  public:
   ArmVIXLAssemblerTest() : pool(), allocator(&pool), assembler(&allocator) { }
 
-  ArenaPool pool;
+  MallocArenaPool pool;
   ArenaAllocator allocator;
   ArmVIXLJNIMacroAssembler assembler;
 };