Fix erroneous behaviors with OOME present.

Bug: 16454510
Change-Id: I757088a7b82ff73f58aba8d357080028b56442e6
diff --git a/runtime/native/java_lang_Class.cc b/runtime/native/java_lang_Class.cc
index e577c2c..124bdf5 100644
--- a/runtime/native/java_lang_Class.cc
+++ b/runtime/native/java_lang_Class.cc
@@ -71,7 +71,10 @@
     jthrowable cnfe = reinterpret_cast<jthrowable>(env->NewObject(WellKnownClasses::java_lang_ClassNotFoundException,
                                                                   WellKnownClasses::java_lang_ClassNotFoundException_init,
                                                                   javaName, cause.get()));
-    env->Throw(cnfe);
+    if (cnfe != nullptr) {
+      // Make sure allocation didn't fail with an OOME.
+      env->Throw(cnfe);
+    }
     return nullptr;
   }
   if (initialize) {