Add gl::gl_type()

[sotaroikeda]

Fixes #104.

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This change is 

[sotaroikeda]

r? @kvark

[kvark]

I don't think gl_type method itself is needed. The client can just do GlType directly or call Default::default() when the type is expected.
@sotaroikeda do you mind removing the gl_type method?

[sotaroikeda]

@kvark , I am thinking to use gl_type () for #99. How can we detect current gl type without gl_type ()?

[sotaroikeda]

@kvark , if you have another idea to detect current gl context type for dynamic gl type selection(#99), can you give me your idea?

[emilio]

How is this decided dynamically at all with this patch? Or is this preliminar work only?

[sotaroikeda]

This preliminar work only. I created #104, since this function could exit on both static and dynamic gl type selection.
WIP patch is in https://bugzilla.mozilla.org/show_bug.cgi?id=1325911.

[kvark]

@sotaroikeda sorry, this PR slipped past me...
You don't need gl_type() function itself. Where GlType is expected, one can just do Default::default().

[sotaroikeda]

Sorry, I did not get your point well. Ok, I removed gl_type(). @kvark, can you review again?

[kvark]

Thanks!
@bors-servo r+

[bors-servo]

📌 Commit 25ef544 has been approved by kvark

[bors-servo]

⌛ Testing commit 25ef544 with merge 8d1c49b...

[bors-servo]

☀️ Test successful - status-travis

[kvark]

@sotaroikeda gleam-v0.2.32 is published now: https://crates.io/crates/gleam/0.2.32