Don't request a heap trim in dex2oat

Change-Id: I5711b8825ccdb68c1e57fe8f85729c723cd11994
diff --git a/src/heap.cc b/src/heap.cc
index 2b5be9c..cda2202 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -730,6 +730,10 @@
     // (This percentage was picked arbitrarily.)
     return;
   }
+  if (!Runtime::Current()->IsStarted()) {
+    // Heap trimming isn't supported without a Java runtime (such as at dex2oat time)
+    return;
+  }
   JNIEnv* env = Thread::Current()->GetJniEnv();
   static jclass Daemons_class = CacheClass(env, "java/lang/Daemons");
   static jmethodID Daemons_requestHeapTrim = env->GetStaticMethodID(Daemons_class, "requestHeapTrim", "()V");