Backed out 2 changesets (bug 939276) because of build bustage

Backed out changeset 1cedc759f877 (bug 939276)
Backed out changeset 61cef3b533ba (bug 939276)

--HG--
rename : gfx/gl/SkiaGLGlue.cpp => gfx/gl/GLContextSkia.cpp
Bug 973088. Use nsContentUtils::GetSecurityManager(). r=ehsan

Faster and more like C++
Bug 784739 follow-up: Use NULL in npruntime.h