Enable strict-virtual-specifiers for iOS builds.

ios/public/test/fake_profile_oauth2_token_service_ios_provider.h

Index: ios/public/test/fake_profile_oauth2_token_service_ios_provider.h
diff --git a/ios/public/test/fake_profile_oauth2_token_service_ios_provider.h b/ios/public/test/fake_profile_oauth2_token_service_ios_provider.h
index 0fdd493aec069bf1b397059e72c625ce3c030ecb..9eca4323fcfd914874b06a8a2fd184e6f42cb727 100644
--- a/ios/public/test/fake_profile_oauth2_token_service_ios_provider.h
+++ b/ios/public/test/fake_profile_oauth2_token_service_ios_provider.h
@@ -19,20 +19,20 @@ class FakeProfileOAuth2TokenServiceIOSProvider
     : public ProfileOAuth2TokenServiceIOSProvider {
  public:
   FakeProfileOAuth2TokenServiceIOSProvider();
-  virtual ~FakeProfileOAuth2TokenServiceIOSProvider();
+  ~FakeProfileOAuth2TokenServiceIOSProvider() override;
 
   // ProfileOAuth2TokenServiceIOSProvider
-  virtual void InitializeSharedAuthentication() override;
+  void InitializeSharedAuthentication() override;
 
-  virtual void GetAccessToken(const std::string& account_id,
-                              const std::string& client_id,
-                              const std::string& client_secret,
-                              const std::set<std::string>& scopes,
-                              const AccessTokenCallback& callback) override;
+  void GetAccessToken(const std::string& account_id,
+                      const std::string& client_id,
+                      const std::string& client_secret,
+                      const std::set<std::string>& scopes,
+                      const AccessTokenCallback& callback) override;
 
-  virtual std::vector<std::string> GetAllAccountIds() override;
+  std::vector<std::string> GetAllAccountIds() override;
 
-  virtual AuthenticationErrorCategory GetAuthenticationErrorCategory(
+  AuthenticationErrorCategory GetAuthenticationErrorCategory(
       NSError* error) const override;
 
   // Methods to configure this fake provider.