Rebaselining after r126911, r127163 and r127534.

Adding a platform-specific baseline for accessibility/canvas-description-and-role.html
that's required after r127084. The baseline is currently the same as Chromium's,
expecting 'AXCanvas' as the AXRole for the canvas element. The GTK port currently
reports 'image' as the AXRole - this is probably not intended so the text failure
expectation is also added for this test.

* platform/gtk/TestExpectations:
* platform/gtk/accessibility/canvas-description-and-role-expected.txt: Added.
* platform/gtk/fast/block/float/024-expected.txt:
* platform/gtk/fast/block/margin-collapse/025-expected.txt:
* platform/gtk/fast/block/margin-collapse/block-inside-inline/025-expected.txt:
* platform/gtk/fast/block/margin-collapse/empty-clear-blocks-expected.txt:
* platform/gtk/fast/css/absolute-child-with-percent-height-inside-relative-parent-expected.txt: Added.
* platform/gtk/fast/inline/absolute-positioned-inline-in-centred-block-expected.txt: Added.
* platform/gtk/fast/inline/left-right-center-inline-alignment-in-ltr-and-rtl-blocks-expected.txt: Added.
* platform/gtk/fast/innerHTML/innerHTML-iframe-expected.txt: Added.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@127565 268f45cc-cd09-0410-ab3c-d52691b4dbfc