We added script to specify overflow: hidden on -webkit-media-controls when the placeholder is showing in r201355 but that code needs to update after r201474. After r201474, we defer removing the hidden class from inlinePlaybackPlaceholder until showInlinePlaybackPlaceholderWhenSafe(). We also need to move the code that adds the placeholder-showing class to -webkit-media-controls to that method. <rdar://problem/26633830>
Created attachment 280508 [details] Patch
Committed: http://trac.webkit.org/changeset/201691