[ios] Adds signin resources and styled text fields to ChromiumBrowserProvider.

ios/chrome/browser/providers/signin/chromium_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_CHROME_BROWSER_PROVIDERS_SIGNIN_CHROMIUM_SIGNIN_RESOURCES_PROVIDER_H_
+#define IOS_CHROME_BROWSER_PROVIDERS_SIGNIN_CHROMIUM_SIGNIN_RESOURCES_PROVIDER_H_
+
+#include "base/macros.h"
+#include "ios/public/provider/chrome/browser/signin/signin_resources_provider.h"
+
+// ChromiumSigninResourcesProvider provides resources that the app expects to
+// exist, even when signin is disabled.
+class ChromiumSigninResourcesProvider : public ios::SigninResourcesProvider {
+ public:
+  ChromiumSigninResourcesProvider();
+  ~ChromiumSigninResourcesProvider() override;
+
+  // SigninResourcesProvider implementation:
+  UIImage* GetDefaultAvatar() override;
+  NSString* GetLocalizedString(ios::SigninStringID string_id) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChromiumSigninResourcesProvider);
+};
+
+#endif  // IOS_CHROME_BROWSER_PROVIDERS_SIGNIN_CHROMIUM_SIGNIN_RESOURCES_PROVIDER_H_