This change removes usage of global Gerrit.DocsUrlBehavior and replace it with direct import. Also, the DocsUrlMixin is removed, because it was introduced as a workaround for polylint tests and is no longer needed. This commit contains the fix for https://gerrit-review.googlesource.com/c/gerrit/+/260133 (which was reverted by https://gerrit-review.googlesource.com/c/gerrit/+/261692). The fix affects only one file: docs-url-behavior.js Change-Id: I09aa39036e40b4a824054088f2857b0eb54d3b39