Add plumbing for accessing latest country in variations service in Java

chrome/browser/android/metrics/variations_session.cc

 // Copyright 2015 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 "chrome/browser/android/metrics/variations_session.h"
 
 #include "base/android/jni_string.h"
 #include "chrome/browser/browser_process.h"
 #include "components/variations/service/variations_service.h"
 #include "jni/VariationsSession_jni.h"
@@ skipping 21 matching lines @@
   if (variations_service) {
     std::string restrict_mode =
         base::android::ConvertJavaStringToUTF8(env, jrestrict_mode);
     if (!restrict_mode.empty() && !g_on_app_enter_foreground_called)
       variations_service->SetRestrictMode(restrict_mode);
     variations_service->OnAppEnterForeground();
     g_on_app_enter_foreground_called = true;
   }
 }
 
+static base::android::ScopedJavaLocalRef<jstring> GetLatestCountry(
+    JNIEnv* env,
+    const JavaParamRef<jobject>& obj) {
+  variations::VariationsService* variations_service =
+      g_browser_process->variations_service();
+  if (!variations_service)
+    return nullptr;
+
+  std::string latest_country = variations_service->GetLatestCountry();
+  if (latest_country.empty())
+    return nullptr;
+
+  return base::android::ConvertUTF8ToJavaString(env, latest_country);
+}
+
 namespace chrome {
 namespace android {
 
 // Register native methods
 bool RegisterVariationsSession(JNIEnv* env) { return RegisterNativesImpl(env); }
 
 }  // namespace android
 }  // namespace chrome