Support for GrDirectContext::MakeGL with GrGLInterface

[Sm0keySa1m0n]

GrDirectContext provides the ability to pass in a GrGLInterface into the MakeGL method (as well as GrContextOptions). It would be useful if Skija added support for this method in DirectContext. This would allow better integration into existing applications using OpenGL that need more control over the OpenGL state. At the moment Skia will modify the GL state on its own making it harder for applications to keep track of it.