Consider a page with the following markup: <!DOCTYPE html> <html> <body> <embed width="640" height="480" type="application/x-shockwave-flash" src="https://www.youtube.com/v/UF8uR6Z6KLc"> </body> </html> If you view this page with plugin replacement enabled (enabled by default on iOS) then the computed width of the video is auto and is clearly less than the specified 640px.
Created attachment 284170 [details] Example For convenience, a page with the markup in comment 0.
Created attachment 284171 [details] Patch and Layout Tests
*** Bug 159973 has been marked as a duplicate of this bug. ***
<rdar://problem/27462285>
Committed r203522: <http://trac.webkit.org/changeset/203522>