Remove ENABLE_3D_PLUGIN
https://bugs.webkit.org/show_bug.cgi?id=108002

Source/WebCore:

Remove ENABLE_3D_PLUGIN, it was only used by Chromium.

Reviewed by Antti Koivisto.

No new tests, removing dead code.

* loader/SubframeLoader.cpp:
(WebCore::SubframeLoader::loadPlugin):

Source/WTF:

Reviewed by Antti Koivisto.

Remove ENABLE_3D_PLUGIN, it was only used by Chromium.

* wtf/FeatureDefines.h:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148093 268f45cc-cd09-0410-ab3c-d52691b4dbfc