gl: Clean up gfx::AcceleratedWidget usage in gl_surface_egl

ui/gl/gl_surface_win.cc

Index: ui/gl/gl_surface_win.cc
diff --git a/ui/gl/gl_surface_win.cc b/ui/gl/gl_surface_win.cc
index 6307f14029a81b64d8f471ad132861b12c606681..7540b1fc35d6125c14f3aef83327cd83bbfe37cc 100644
--- a/ui/gl/gl_surface_win.cc
+++ b/ui/gl/gl_surface_win.cc
@@ -12,6 +12,7 @@
 #include "base/win/windows_version.h"
 #include "third_party/mesa/src/include/GL/osmesa.h"
 #include "ui/gfx/frame_time.h"
+#include "ui/gfx/native_widget_types.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface_egl.h"
@@ -228,6 +229,7 @@ scoped_refptr<GLSurface> GLSurface::CreateViewGLSurface(
       return surface;
     }
     case kGLImplementationEGLGLES2: {
+      DCHECK(window != gfx::kNullAcceleratedWidget);
       scoped_refptr<NativeViewGLSurfaceEGL> surface(
           new NativeViewGLSurfaceEGL(window));
       scoped_ptr<VSyncProvider> sync_provider;