windows opengl: Implement WinOpenGLSalGraphicsImpl::Init() too.
windows opengl: Implement WinOpenGLSalGraphicsImpl::Init() too.

[Blind fix to fix build; real fix to follow after testing.]

Change-Id: Ic4cf2dc74ba4649a2453bc351cdc1d1fad59a0ca

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core