Ensure real GL Api is set before making GL calls.

ui/gl/gl_context_osmesa.cc

Index: ui/gl/gl_context_osmesa.cc
diff --git a/ui/gl/gl_context_osmesa.cc b/ui/gl/gl_context_osmesa.cc
index 71154eca0974a1d1ca1930cbbc1b5fce50663722..cb71aa57a7e1a059ad73ef2e27cc6cfd6ccbb12a 100644
--- a/ui/gl/gl_context_osmesa.cc
+++ b/ui/gl/gl_context_osmesa.cc
@@ -62,6 +62,9 @@ bool GLContextOSMesa::MakeCurrent(GLSurface* surface) {
     return false;
   }
 
+  // Set this as soon as the context is current, since we might call into GL.
+  SetRealGLApi();
+
   // Row 0 is at the top.
   OSMesaPixelStore(OSMESA_Y_UP, 0);
 
@@ -76,7 +79,6 @@ bool GLContextOSMesa::MakeCurrent(GLSurface* surface) {
     return false;
   }
 
-  SetRealGLApi();
   return true;
 }