jni_generator: Wrap all native methods in stubs.

base/android/jni_generator/testNativeExportsOption.golden

Index: base/android/jni_generator/testNativeExportsOption.golden
diff --git a/base/android/jni_generator/testNativeExportsOption.golden b/base/android/jni_generator/testNativeExportsOption.golden
index 395fc390e34f1475f8d276ef39c0c04ba2064fde..3bd284701f52396ec5957be3818d9ebb7eda9af6 100644
--- a/base/android/jni_generator/testNativeExportsOption.golden
+++ b/base/android/jni_generator/testNativeExportsOption.golden
@@ -26,11 +26,9 @@ base::subtle::AtomicWord g_SampleForTests_clazz __attribute__((unused)) = 0;
 
 }  // namespace
 
-extern "C" {
-
 static jint Init(JNIEnv* env, jobject jcaller);
 
-__attribute__((visibility("default")))
+extern "C" __attribute__((visibility("default")))
 jint
     Java_org_chromium_example_jni_1generator_SampleForTests_00024MyInnerClass_nativeInit(JNIEnv*
     env, jobject jcaller) {
@@ -39,19 +37,15 @@ jint
 
 static jint Init(JNIEnv* env, jobject jcaller);
 
-__attribute__((visibility("default")))
+extern "C" __attribute__((visibility("default")))
 jint
     Java_org_chromium_example_jni_1generator_SampleForTests_00024MyOtherInnerClass_nativeInit(JNIEnv*
     env, jobject jcaller) {
   return Init(env, jcaller);
 }
 
-};  // extern "C"
-
 // Step 2: method stubs.
-
-extern "C" {
-__attribute__((visibility("default")))
+extern "C" __attribute__((visibility("default")))
 jint
     Java_org_chromium_example_jni_1generator_SampleForTests_nativeStaticMethod(JNIEnv*
     env,
@@ -63,7 +57,7 @@ jint
   return native->StaticMethod(env, jcaller, arg1);
 }
 
-__attribute__((visibility("default")))
+extern "C" __attribute__((visibility("default")))
 jint
     Java_org_chromium_example_jni_1generator_SampleForTests_nativeMethod(JNIEnv*
     env,
@@ -198,7 +192,6 @@ static_cast<jstring>(env->CallStaticObjectMethod(SampleForTests_clazz(env),
   jni_generator::CheckException(env);
   return base::android::ScopedJavaLocalRef<jstring>(env, ret);
 }
-};  // extern "C"
 
 // Step 3: RegisterNatives.