[ios] Adds a TestSigninResourceProvider to TestChromeBrowserProvider.

ios/public/provider/chrome/browser/signin/test_signin_resources_provider.h

+// Copyright 2016 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 IOS_PUBLIC_PROVIDER_CHROME_BROWSER_SIGNIN_TEST_SIGNIN_RESOURCES_PROVIDER_H_
+#define IOS_PUBLIC_PROVIDER_CHROME_BROWSER_SIGNIN_TEST_SIGNIN_RESOURCES_PROVIDER_H_
+
+#include "ios/public/provider/chrome/browser/signin/signin_resources_provider.h"
+
+#include "base/mac/scoped_nsobject.h"
+
+@class UIImage;
+
+class TestSigninResourcesProvider : public ios::SigninResourcesProvider {
+ public:
+  TestSigninResourcesProvider();
+  ~TestSigninResourcesProvider() override;
+
+  UIImage* GetDefaultAvatar() override;
+  NSString* GetLocalizedString(ios::SigninStringID string_id) override;
+
+ private:
+  base::scoped_nsobject<UIImage> default_avatar_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestSigninResourcesProvider);
+};
+
+#endif  // IOS_PUBLIC_PROVIDER_CHROME_BROWSER_SIGNIN_TEST_SIGNIN_RESOURCES_PROVIDER_H_