ART: Make RuntimeCallbacks unique_ptr

Reduce the transitive closure of headers on runtime.h

Test: m
Change-Id: Ib5a3632c28b08bf07773f217a7ad711c1f12af6b
diff --git a/runtime/runtime_callbacks_test.cc b/runtime/runtime_callbacks_test.cc
index 8cd39a0..f05794d 100644
--- a/runtime/runtime_callbacks_test.cc
+++ b/runtime/runtime_callbacks_test.cc
@@ -96,10 +96,10 @@
 
  protected:
   void AddListener() OVERRIDE REQUIRES(Locks::mutator_lock_) {
-    Runtime::Current()->GetRuntimeCallbacks().AddThreadLifecycleCallback(&cb_);
+    Runtime::Current()->GetRuntimeCallbacks()->AddThreadLifecycleCallback(&cb_);
   }
   void RemoveListener() OVERRIDE REQUIRES(Locks::mutator_lock_) {
-    Runtime::Current()->GetRuntimeCallbacks().RemoveThreadLifecycleCallback(&cb_);
+    Runtime::Current()->GetRuntimeCallbacks()->RemoveThreadLifecycleCallback(&cb_);
   }
 
   enum CallbackState {
@@ -215,10 +215,10 @@
 class ClassLoadCallbackRuntimeCallbacksTest : public RuntimeCallbacksTest {
  protected:
   void AddListener() OVERRIDE REQUIRES(Locks::mutator_lock_) {
-    Runtime::Current()->GetRuntimeCallbacks().AddClassLoadCallback(&cb_);
+    Runtime::Current()->GetRuntimeCallbacks()->AddClassLoadCallback(&cb_);
   }
   void RemoveListener() OVERRIDE REQUIRES(Locks::mutator_lock_) {
-    Runtime::Current()->GetRuntimeCallbacks().RemoveClassLoadCallback(&cb_);
+    Runtime::Current()->GetRuntimeCallbacks()->RemoveClassLoadCallback(&cb_);
   }
 
   bool Expect(std::initializer_list<const char*> list) {