No need to keep anonymous RenderBlock in DETAILS.

No need to keep anonymous RenderBlock in DETAILS.
https://bugs.webkit.org/show_bug.cgi?id=77322

Patch by Shinya Kawanaka <shinyak@google.com> on 2012-01-30
Reviewed by Hajime Morita.

Anonymous RenderBlock of DETAILS element was not squashed when detaching them.
However, it should be removed.

No new tests. Should be covered by existing tests.

* rendering/RenderBlock.cpp:
(WebCore::canMergeContiguousAnonymousBlocks):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@106228 268f45cc-cd09-0410-ab3c-d52691b4dbfc