Refactor GL bindings so there is no global GLApi or DriverGL.

ui/gl/init/gl_factory_win.cc

Index: ui/gl/init/gl_factory_win.cc
diff --git a/ui/gl/init/gl_factory_win.cc b/ui/gl/init/gl_factory_win.cc
index 97760c459974b3f31436810bb3467289fb0cd939..bf0640c2a4a779b0fba624b088e106ddb2b34343 100644
--- a/ui/gl/init/gl_factory_win.cc
+++ b/ui/gl/init/gl_factory_win.cc
@@ -61,6 +61,12 @@ scoped_refptr<GLContext> CreateGLContext(GLShareGroup* share_group,
                                  compatible_surface, attribs);
     case kGLImplementationMockGL:
       return new GLContextStub(share_group);
+    case kGLImplementationStubGL: {
+      scoped_refptr<GLContextStub> stub_context =
+          new GLContextStub(share_group);
+      stub_context->SetUseStubApi(true);
+      return stub_context;
+    }
     default:
       NOTREACHED();
       return nullptr;
@@ -86,6 +92,7 @@ scoped_refptr<GLSurface> CreateViewGLSurface(gfx::AcceleratedWidget window) {
     case kGLImplementationDesktopGL:
       return InitializeGLSurface(new NativeViewGLSurfaceWGL(window));
     case kGLImplementationMockGL:
+    case kGLImplementationStubGL:
       return new GLSurfaceStub;
     default:
       NOTREACHED();
@@ -108,6 +115,7 @@ scoped_refptr<GLSurface> CreateOffscreenGLSurfaceWithFormat(
       return InitializeGLSurfaceWithFormat(
           new PbufferGLSurfaceWGL(size), format);
     case kGLImplementationMockGL:
+    case kGLImplementationStubGL:
       return new GLSurfaceStub;
     default:
       NOTREACHED();