Follow-up fixes to changing namespace gfx to gl.

ui/gl/gl_context_stub_with_extensions.h

Index: ui/gl/gl_context_stub_with_extensions.h
diff --git a/ui/gl/gl_context_stub_with_extensions.h b/ui/gl/gl_context_stub_with_extensions.h
index 3d4f7993cb74e1bdd3c1f1ea1994e7ab2c9f7f4c..f586c397cb5f1766b352a8cd3f4a0352b9292dc4 100644
--- a/ui/gl/gl_context_stub_with_extensions.h
+++ b/ui/gl/gl_context_stub_with_extensions.h
@@ -14,7 +14,7 @@ namespace gl {
 // Lightweight GLContext stub implementation that returns a constructed
 // extensions string.  We use this to create a context that we can use to
 // initialize GL extensions with, without actually creating a platform context.
-class GL_EXPORT GLContextStubWithExtensions : public gl::GLContextStub {
+class GL_EXPORT GLContextStubWithExtensions : public GLContextStub {
  public:
   GLContextStubWithExtensions() {}
   std::string GetExtensions() override;