[ios] Change WeakKeysAreInvalid to return false on iOS 13.

As of Xcode 11 beta 5, it appears iOS is now setting CERT_STATUS_WEAK_KEY
properly.

Bug: 977163
Change-Id: I8bc713eb8d20914410c1aa642932a4c615235ede
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1725539Reviewed-by: Ryan Sleevi <rsleevi@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682301}

net/cert/cert_verify_proc_unittest.cc

@@ -875,14 +875,7 @@ class CertVerifyProcInternalTest
   }
 
   bool WeakKeysAreInvalid() const {
-#if defined(OS_IOS)
-    // Starting with iOS 13, certs with weak keys are treated as (recoverable)
-    // invalid certificate errors.
-    if (verify_proc_type() == CERT_VERIFY_PROC_IOS &&
-        base::ios::IsRunningOnIOS13OrLater()) {
-      return true;
-    }
-#elif defined(OS_MACOSX)
+#if defined(OS_MACOSX) and !defined(OS_IOS)
     // Starting with Mac OS 10.12, certs with weak keys are treated as
     // (recoverable) invalid certificate errors.
     if (verify_proc_type() == CERT_VERIFY_PROC_MAC &&