Correct SecTrustResultType init for latest Xcode beta.

ios/web/web_state/wk_web_view_security_util_unittest.mm

 // Copyright 2015 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.
 
 #import "ios/web/web_state/wk_web_view_security_util.h"
 
 #import <Foundation/Foundation.h>
 #include <Security/Security.h>
 
 #include <memory>
@@ skipping 69 matching lines @@
 TEST_F(WKWebViewSecurityUtilTest, CreationCertFromEmptyChain) {
   EXPECT_FALSE(CreateCertFromChain(@[]));
 }
 
 // Tests MakeTrustValid with self-signed cert.
 TEST_F(WKWebViewSecurityUtilTest, MakingTrustValid) {
   // Create invalid trust object.
   base::ScopedCFTypeRef<SecTrustRef> trust =
       CreateTestTrust(MakeTestCertChain(kTestSubject));
 
-  SecTrustResultType result = -1;
+  SecTrustResultType result = kSecTrustResultInvalid;
   SecTrustEvaluate(trust, &result);
   EXPECT_EQ(kSecTrustResultRecoverableTrustFailure, result);
 
   // Make sure that trust becomes valid after
   // |EnsureFutureTrustEvaluationSucceeds| call.
   EnsureFutureTrustEvaluationSucceeds(trust);
   SecTrustEvaluate(trust, &result);
   EXPECT_EQ(kSecTrustResultProceed, result);
 }
 
@@ skipping 175 matching lines @@
             GetSecurityStyleFromTrustResult(kSecTrustResultUnspecified));
 }
 
 // Tests GetSecurityStyleFromTrustResult with invalid SecTrustResultType result.
 TEST_F(WKWebViewSecurityUtilTest, GetSecurityStyleFromInvalidResult) {
   EXPECT_EQ(SECURITY_STYLE_UNKNOWN,
             GetSecurityStyleFromTrustResult(kSecTrustResultInvalid));
 }
 
 }  // namespace web