[BlackBerry] LayerTexture: check if the graphics context is NULL
https://bugs.webkit.org/show_bug.cgi?id=114674

Patch by Anthony Scian <ascian@blackberry.com> on 2013-04-16
Reviewed by Rob Buis.

Internal PR: 256522

* platform/graphics/blackberry/LayerTexture.cpp:
(WebCore::LayerTexture::setContentsToColor):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148516 268f45cc-cd09-0410-ab3c-d52691b4dbfc