When GLVisualPickerGLX was written, the only way of obtaining
GL-compatible visuals was with libGLX, which loads the GPU driver.
This forced us to rely on the GPU process sending the visuals to the
browser process, which comes with a significant amount of complexity.
Now that we've switched to XProto, we can use x11::Glx to obtain the
visuals, which doesn't require loading the GPU driver. This allows
us to simplify the visual loading code.
In addition, now that the transparent visual is available early, it
can be used as the visual for browser windows. This can allow us to
remove usage of the XShape extension which we were using to "cut off"
a few pixels around the corners to give the appearance of rounded
corners. This solution is not ideal since it:
1. causes a performance hit on some environments (GNOME/Mutter)
2. prevents the WM from drawing a shadow on the window
3. doesn't antialias the corners
Using a transparent visual will solve all 3 issues. However, we'll
have to draw client-side shadows (just like GTK does).
R=sky
Bug: 650494,811515,1198080
Change-Id: Ie518dfe489d3ba0af9ca73c80cc10792a4214838
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2895228
Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Emily Stark <estark@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Commit-Queue: Emily Stark <estark@chromium.org>
Auto-Submit: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#884257}
