jni_generator: Pass object parameters as JavaParamRef.

base/message_loop/message_pump_android.cc

Index: base/message_loop/message_pump_android.cc
diff --git a/base/message_loop/message_pump_android.cc b/base/message_loop/message_pump_android.cc
index babd17b577ec0d45886bf88b81166837ddc46d0d..a0eee12c85c3034e9b42ec82d259e96619b06759 100644
--- a/base/message_loop/message_pump_android.cc
+++ b/base/message_loop/message_pump_android.cc
@@ -21,8 +21,10 @@ using base::android::ScopedJavaLocalRef;
 // ----------------------------------------------------------------------------
 // This method can not move to anonymous namespace as it has been declared as
 // 'static' in system_message_handler_jni.h.
-static void DoRunLoopOnce(JNIEnv* env, jobject obj, jlong native_delegate,
-    jlong delayed_scheduled_time_ticks) {
+static void DoRunLoopOnce(JNIEnv* env,
+                          const JavaParamRef<jobject>& obj,
+                          jlong native_delegate,
+                          jlong delayed_scheduled_time_ticks) {
   base::MessagePump::Delegate* delegate =
       reinterpret_cast<base::MessagePump::Delegate*>(native_delegate);
   DCHECK(delegate);