https://bugs.webkit.org/show_bug.cgi?id=109475

Reviewed by Martin Robinson.

Source/WebCore: 

No new tests - majority of the related tests now passes.

* GNUmakefile.features.am.in: Add the feature define for the CSS image-set feature
with the define value defaulting to 0. The value gets overridden with 1 in development
builds, meaning the feature is enabled under that configuration.

Tools: 

* Scripts/webkitperl/FeatureList.pm: Add the configuration option for the feature.
Note that the Mac port also enables the feature but does so in Platform.h as the feature
is also enabled for the iOS port which can't at the moment be detected via webkitperl.

LayoutTests: 

* platform/gtk/TestExpectations: Reclassify two failures that now fail due to
cursor images not loading while the other expectations are removed as the tests
now pass.
* platform/gtk/fast/css/image-set-value-not-removed-crash-expected.txt: Removed. The generic
expectation now matches the test output.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@142606 268f45cc-cd09-0410-ab3c-d52691b4dbfc