We have an angular directive <pre piwik-select-on-focus>...</pre> to select for example a code block with just one click. This is used for example when generating the tracking code. It is also used in other places for example by the Widgets screen to select a link or HTML, by Custom Dimensions, by plugins like A/B testing etc.

This is likely due to https://www.chromestatus.com/feature/6680566019653632

It likely still works for <textarea piwik-select-on-focus>...</textarea> but not for any other element.