MW has a mechanism for declaring whether or not a skin is "responsive": setting the responsive option when the skin (Skin class) is constructed. Once a skin is declared to be responsive, users can individually specify whether or not they want responsiveness, and the joint result is exposed via the public function Skin::isResponsive().

Based on the result of Skin::isResponsive(), MW adds one of two <meta> tags to page output:

• If isResponsive: <meta name="viewport" content="width=device-width, initial-scale=1.0, user-scalable=yes, minimum-scale=0.25, maximum-scale=5.0"/>
• If not isResponsive: <meta name="viewport" content="width=1000"/>

(See Skin::initPage().)

Chameleon is a responsive skin, but it does not tell that to the MW core via the responsive option to Skin. Instead, it manually adds a viewport specification to the page output, via Chameleon::initPage() (after calling parent::initPage():

• <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no"/>

As a result:

1. the MW core and other extensions will always get a false result from Skin::isResponsive(), and consider chameleon to be not-responsive.
2. Every wiki page has two viewport tags, with competing width values: 1000 from MW core, and device-width from chameleon.

I noticed this because chrome-based browsers on Android (e.g., Chromium, Vanadium, Brave) appear to favor the width=1000 depending on the page content. E.g., pages with long unbroken strings (like visible URLs) are mysteriously rendered as "unresponsive" fixed-width.

My recommendations for fixing this:

• Add 'responsive' => true to the list of options to Chameleon in SetupAfterCache::registerSkinWithMW().
• Remove Chameleon::initPage() (since all it does is add the superfluous viewport tag).

(These recommendations appear to work for me.)