ART: Whitelist DexPathList$Element constructor

Temporary whitelist for backwards compatibility.

Bug: 20699073
Change-Id: Iba351060441398b9377a8471f0bbe03bb77f8384
diff --git a/runtime/native/java_lang_reflect_Constructor.cc b/runtime/native/java_lang_reflect_Constructor.cc
index 908089e..f74102e 100644
--- a/runtime/native/java_lang_reflect_Constructor.cc
+++ b/runtime/native/java_lang_reflect_Constructor.cc
@@ -51,10 +51,17 @@
     // If caller is null, then we called from JNI, just avoid the check since JNI avoids most
     // access checks anyways. TODO: Investigate if this the correct behavior.
     if (caller != nullptr && !caller->CanAccess(c.Get())) {
-      soa.Self()->ThrowNewExceptionF(
-          "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
-          PrettyClass(c.Get()).c_str(), PrettyClass(caller).c_str());
-      return nullptr;
+      if (PrettyDescriptor(c.Get()) == "dalvik.system.DexPathList$Element") {
+        // b/20699073.
+        LOG(WARNING) << "The dalvik.system.DexPathList$Element constructor is not accessible by "
+                        "default. This is a temporary workaround for backwards compatibility "
+                        "with class-loader hacks. Please update your application.";
+      } else {
+        soa.Self()->ThrowNewExceptionF(
+            "Ljava/lang/IllegalAccessException;", "%s is not accessible from %s",
+            PrettyClass(c.Get()).c_str(), PrettyClass(caller).c_str());
+        return nullptr;
+      }
     }
   }
   if (!Runtime::Current()->GetClassLinker()->EnsureInitialized(soa.Self(), c, true, true)) {