jni: Pass method parameters as JavaParamRef in base.

base/android/java_handler_thread.h

Index: base/android/java_handler_thread.h
diff --git a/base/android/java_handler_thread.h b/base/android/java_handler_thread.h
index c9a2c02d3546ed3ffb557061db65f06bc487cd8f..07715a87b9bb3dc98eebfa1cb44cc71bd5452c06 100644
--- a/base/android/java_handler_thread.h
+++ b/base/android/java_handler_thread.h
@@ -33,8 +33,12 @@ class BASE_EXPORT JavaHandlerThread {
 
   // Called from java on the newly created thread.
   // Start() will not return before this methods has finished.
-  void InitializeThread(JNIEnv* env, jobject obj, jlong event);
-  void StopThread(JNIEnv* env, jobject obj, jlong event);
+  void InitializeThread(JNIEnv* env,
+                        const JavaParamRef<jobject>& obj,
+                        jlong event);
+  void StopThread(JNIEnv* env,
+                  const JavaParamRef<jobject>& obj,
+                  jlong event);
 
   static bool RegisterBindings(JNIEnv* env);