Remove variable shadowing in blink/modules/credentialmanager

In an effort to reduce or even ban variable shadowing, this renames
a variable to avoid such shadowing. I'm interested in prohibiting
shadowing because I think it might prevent potential jumbo problems.

The exact error this avoids is:
third_party/blink/renderer/modules/credentialmanager/credentials_container.cc:180:23: error: declaration shadows a local variable [-Werror,-Wshadow]
    OriginAccessEntry access_entry(
                      ^
third_party/blink/renderer/modules/credentialmanager/credentials_container.cc:166:21: note: previous declaration is here
  OriginAccessEntry access_entry(
                    ^

Bug: 923510
Change-Id: I61b11ecd489ed9842e1a9ebee9293050f7f1cde5
Reviewed-on: https://chromium-review.googlesource.com/c/1478890Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Daniel Bratell <bratell@opera.com>
Cr-Commit-Position: refs/heads/master@{#633742}

third_party/blink/renderer/modules/credentialmanager/credentials_container.cc

@@ -163,10 +163,14 @@ bool CheckPublicKeySecurityRequirements(ScriptPromiseResolver* resolver,
 
   // TODO(crbug.com/803077): Avoid constructing an OriginAccessEntry just
   // for the IP address check.
+  bool reject_because_invalid_domain = effective_domain.IsEmpty();
+  if (!reject_because_invalid_domain) {
     OriginAccessEntry access_entry(
         origin->Protocol(), effective_domain,
         network::mojom::CorsOriginAccessMatchMode::kAllowSubdomains);
-  if (effective_domain.IsEmpty() || access_entry.HostIsIPAddress()) {
+    reject_because_invalid_domain = access_entry.HostIsIPAddress();
+  }
+  if (reject_because_invalid_domain) {
     resolver->Reject(
         DOMException::Create(DOMExceptionCode::kSecurityError,
                              "Effective domain is not a valid domain."));