grammar-markers.html and grammar-markers-hidpi.html pass even if element does not have grammar marker
https://bugs.webkit.org/show_bug.cgi?id=119797

Reviewed by Ryosuke Niwa.

After tenth attempts of verifying the grammar marker, the tests call'notifyDone'
even if grammar marker was not be found.

Both grammar-marker.html and grammar-marker-hidpi.html call the text checker
asynchronously. Therefore, we need to wait until either the grammar marker
is found or number of attempts is reached.

Dump more information whether the grammar marker was found to be sure that
the tests do not pass when the element does not have the marker.

* editing/spelling/grammar-markers-expected.txt:
* editing/spelling/grammar-markers-hidpi-expected.txt:
Update the expectations.

* editing/spelling/grammar-markers-hidpi.html:
* editing/spelling/grammar-markers.html:
Dump more information.
Additionally, pass 'document' to hasGrammarMarker instead of
'target' as the method does not work for target/source elements.

* platform/mac/editing/spelling/grammar-markers-expected.png:
* platform/mac/editing/spelling/grammar-markers-hidpi-expected.png: Added.
Update the expectations for Mac.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@154675 268f45cc-cd09-0410-ab3c-d52691b4dbfc