With the Qt port, on all platforms, Qt has a custom stylesheet for the mediacontrols, extending the default one. Clicking on the play button make it grow by 2px. Since r83397 the media controls elements are actual DOM elements. Therefore the global style-sheet applies to them. html.css defines input[type="button"]:active to be border-style: inset which means that when the buttons are active they grow by their border size.
Created attachment 89454 [details] Proposed patch.
Attachment 89454 [details] did not pass style-queue: Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebCore/ChangeLog', u'Source/WebCor..." exit_code: 1 Source/WebCore/ChangeLog:1: ChangeLog entry has no bug number [changelog/bugnumber] [5] Total errors found: 1 in 2 files If any of these errors are false positives, please file a bug against check-webkit-style.
Created attachment 89458 [details] Proposed patch V2 with Changelog fixed.
Comment on attachment 89458 [details] Proposed patch V2 with Changelog fixed. Excellent fix. This takes care of "jiggling" buttons when you click on them.
The commit-queue encountered the following flaky tests while processing attachment 89458 [details]: http/tests/misc/favicon-loads-with-icon-loading-override.html bug 58412 (author: alice.liu@apple.com) The commit-queue is continuing to process your patch.
Comment on attachment 89458 [details] Proposed patch V2 with Changelog fixed. Clearing flags on attachment: 89458 Committed r83847: <http://trac.webkit.org/changeset/83847>
All reviewed patches have been landed. Closing bug.
Turns out this change was wrong. Chromium port does use borders. So this change needs to go deeper into mediaControlsQt and mediaControlsQuickTime. Let's roll this out.
Reverted r83847 for reason: Chromium media controls do use button borders, so this change is incorrect. Committed r83858: <http://trac.webkit.org/changeset/83858>
Created attachment 89652 [details] Proposed patch after breakage of Chromium. We need to disable borders only in ports which are not using them :D.
The commit-queue encountered the following flaky tests while processing attachment 89652 [details]: http/tests/xmlhttprequest/access-control-basic-non-simple-allow-async.html bug 58663 (authors: ap@webkit.org and sam@webkit.org) The commit-queue is continuing to process your patch.
Comment on attachment 89652 [details] Proposed patch after breakage of Chromium. Clearing flags on attachment: 89652 Committed r83973: <http://trac.webkit.org/changeset/83973>