acceptance tests fails on main frame name
Latest viewport changes (10.10.2016) breaks backend acceptance tests.
By issue #52877 backend main frame name-tag has been renamed from content to contentIframe, which is used in about 14 acceptence tests files.
They should be renamed in such acceptance tests too.
There are several changes, which causes further errors and/or failures running existing acceptance tests.
I already tried running acceptance tests with changed name-tags on concerning files, which results in new errors and failures causing other changes. I decided to create separate issues for them, cause they need a focus on their own.
I will set a patch.