Update minimum length for edit distance matching.

This CL updates the minimum length of a domain that is considered for an
edit distance match. Edit distance is used in some cases to trigger a
Safety Tip warning.

Bug: 1023820
Change-Id: Ie4a18369874dbb947a5e1b41f2bf8b189b60403b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1913468
Commit-Queue: Joe DeBlasio <jdeblasio@chromium.org>
Commit-Queue: Mustafa Emre Acer <meacer@chromium.org>
Reviewed-by: Mustafa Emre Acer <meacer@chromium.org>
Auto-Submit: Joe DeBlasio <jdeblasio@chromium.org>
Cr-Commit-Position: refs/heads/master@{#714750}

components/url_formatter/spoof_checks/top_domains/top_domain_util.cc

@@ -11,9 +11,11 @@ namespace top_domains {
 
 namespace {
 
-// Minimum length for a hostname to be considered for an edit distance
-// comparison. Shorter domains are ignored.
-const size_t kMinLengthForEditDistance = 5u;
+// Minimum length of the e2LD (the registered domain name without the registry)
+// to be considered for an edit distance comparison, including a trailing dot.
+// Thus: 'google.com' has of length 7 ("google.") and is long enough, while
+//       'abc.co.uk' has a length of 4 ("abc."), and will not be considered.
+const size_t kMinLengthForEditDistance = 6u;
 
 }  // namespace