[Payment Request] Update the CurrencyStringFormatter to call the native impl.

components/payments/android/currency_formatter_android.h

+// Copyright 2017 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.
+
+#ifndef COMPONENTS_PAYMENTS_ANDROID_CURRENCY_FORMATTER_ANDROID_H_
+#define COMPONENTS_PAYMENTS_ANDROID_CURRENCY_FORMATTER_ANDROID_H_
+
+#include <memory>
+
+#include "base/android/scoped_java_ref.h"
+#include "base/macros.h"
+#include "components/payments/currency_formatter.h"
+
+using base::android::JavaParamRef;

[please use gerrit instead, 2017/01/13 21:16:25]

"using" should not be in header files, as a rule of thumb. I know this results
in bigger header files for us, but those who use this header will thank us for
not polluting the global namespace.

[Mathieu, 2017/01/13 22:27:01]

Done.

+
+namespace payments {
+
+// Forwarding calls to payments::CurrencyFormatter.
+class CurrencyFormatterAndroid {
+ public:
+  CurrencyFormatterAndroid(JNIEnv* env,
+                           jobject unused_obj,
+                           const JavaParamRef<jstring>& currency_code,
+                           const JavaParamRef<jstring>& currency_system,
+                           const JavaParamRef<jstring>& locale_name);
+  ~CurrencyFormatterAndroid();
+
+  // Refer to CurrencyFormatter::Format documentation.
+  base::android::ScopedJavaLocalRef<jstring> Format(
+      JNIEnv* env,
+      const JavaParamRef<jobject>& unused_obj,
+      const JavaParamRef<jstring>& amount);
+
+  // Registers the JNI bindings for this class.
+  static bool Register(JNIEnv* env);
+
+ private:
+  std::unique_ptr<CurrencyFormatter> currency_formatter_;
+
+  DISALLOW_COPY_AND_ASSIGN(CurrencyFormatterAndroid);
+};
+
+}  // namespace payments
+
+#endif  // COMPONENTS_PAYMENTS_ANDROID_CURRENCY_FORMATTER_ANDROID_H_