jni_generator: Make all object-returning natives return ScopedJavaLocalRef.

chrome/browser/android/url_utilities.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "components/google/core/browser/google_util.h"
 #include "components/url_formatter/url_fixer.h"
 #include "jni/UrlUtilities_jni.h"
 #include "net/base/registry_controlled_domains/registry_controlled_domain.h"
@@ skipping 25 matching lines @@
   GURL url_2 = ConvertJavaStringToGURL(env, url_2_str);
 
   net::registry_controlled_domains::PrivateRegistryFilter filter =
       GetRegistryFilter(include_private);
 
   return net::registry_controlled_domains::SameDomainOrHost(url_1,
                                                             url_2,
                                                             filter);
 }
 
-static jstring GetDomainAndRegistry(JNIEnv* env,
-                                    jclass clazz,
-                                    jstring url,
-                                    jboolean include_private) {
+static ScopedJavaLocalRef<jstring> GetDomainAndRegistry(
+    JNIEnv* env,
+    jclass clazz,
+    jstring url,
+    jboolean include_private) {
   DCHECK(url);
   GURL gurl = ConvertJavaStringToGURL(env, url);
   if (gurl.is_empty())
-    return nullptr;
+    return ScopedJavaLocalRef<jstring>();
 
   net::registry_controlled_domains::PrivateRegistryFilter filter =
       GetRegistryFilter(include_private);
 
-  // OK to release, JNI binding.
   return base::android::ConvertUTF8ToJavaString(
-      env, net::registry_controlled_domains::GetDomainAndRegistry(
-          gurl, filter)).Release();
+      env,
+      net::registry_controlled_domains::GetDomainAndRegistry(gurl, filter));
 }
 
 static jboolean IsGoogleSearchUrl(JNIEnv* env, jclass clazz, jstring url) {
   GURL gurl = ConvertJavaStringToGURL(env, url);
   if (gurl.is_empty())
     return false;
   return google_util::IsGoogleSearchUrl(gurl);
 }
 
 static jboolean IsGoogleHomePageUrl(JNIEnv* env, jclass clazz, jstring url) {
   GURL gurl = ConvertJavaStringToGURL(env, url);
   if (gurl.is_empty())
     return false;
   return google_util::IsGoogleHomePageUrl(gurl);
 }
 
-static jstring FixupUrl(JNIEnv* env,
-                        jclass clazz,
-                        jstring url,
-                        jstring optional_desired_tld) {
+static ScopedJavaLocalRef<jstring> FixupUrl(JNIEnv* env,
+                                            jclass clazz,
+                                            jstring url,
+                                            jstring optional_desired_tld) {
   DCHECK(url);
   GURL fixed_url = url_formatter::FixupURL(
       base::android::ConvertJavaStringToUTF8(env, url),
       optional_desired_tld
           ? base::android::ConvertJavaStringToUTF8(env, optional_desired_tld)
           : std::string());
 
-  return fixed_url.is_valid() ?
-      base::android::ConvertUTF8ToJavaString(env, fixed_url.spec()).Release() :
-      nullptr;
+  return fixed_url.is_valid()
+             ? base::android::ConvertUTF8ToJavaString(env, fixed_url.spec())
+             : ScopedJavaLocalRef<jstring>();
 }
 
 // Register native methods
 bool RegisterUrlUtilities(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }