[ios] Adds a TestSigninResourceProvider to TestChromeBrowserProvider.

ios/public/provider/chrome/browser/test_chrome_browser_provider.h

Index: ios/public/provider/chrome/browser/test_chrome_browser_provider.h
diff --git a/ios/public/provider/chrome/browser/test_chrome_browser_provider.h b/ios/public/provider/chrome/browser/test_chrome_browser_provider.h
index 50870a11a98a4231304ab0899ae64f7965abb53a..aeaec1831831b22f7031bfd952ee8d30d99521ea 100644
--- a/ios/public/provider/chrome/browser/test_chrome_browser_provider.h
+++ b/ios/public/provider/chrome/browser/test_chrome_browser_provider.h
@@ -22,6 +22,7 @@ class TestChromeBrowserProvider : public ChromeBrowserProvider {
   static TestChromeBrowserProvider* GetTestProvider();
 
   // ChromeBrowserProvider:
+  SigninResourcesProvider* GetSigninResourcesProvider() override;
   void SetChromeIdentityServiceForTesting(
       std::unique_ptr<ChromeIdentityService> service) override;
   ChromeIdentityService* GetChromeIdentityService() override;
@@ -37,6 +38,7 @@ class TestChromeBrowserProvider : public ChromeBrowserProvider {
   std::unique_ptr<AppDistributionProvider> app_distribution_provider_;
   std::unique_ptr<ChromeIdentityService> chrome_identity_service_;
   std::unique_ptr<OmahaServiceProvider> omaha_service_provider_;
+  std::unique_ptr<SigninResourcesProvider> signin_resources_provider_;
   std::unique_ptr<VoiceSearchProvider> voice_search_provider_;
 
   DISALLOW_COPY_AND_ASSIGN(TestChromeBrowserProvider);