Add Qt specific expected result for a new test introduced in r76074.
Compared to Mac png files and Mac expected files.

* platform/qt/fast/block/float/float-overflow-hidden-containing-block-width-expected.checksum: Added.
* platform/qt/fast/block/float/float-overflow-hidden-containing-block-width-expected.png: Added.
* platform/qt/fast/block/float/float-overflow-hidden-containing-block-width-expected.txt: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@76131 268f45cc-cd09-0410-ab3c-d52691b4dbfc