[GTK] Use DMABuf and WebKit IPC for rendering instead of wpe/x11

• Component: WebKitGTK
• Status: RESOLVED FIXED

[Carlos Garcia Campos]

Instead of the wpe rendered, which uses a nested wayland compositor, and x11, which uses a redirected xcomposito window, we can make the web process render always into a pbuffer using mesa surfaceless platform and export the rendered texture using DMAbuf to be consumed by the UI process. This way the rendering is independent from the platform (wayland/x11), in the UI process we just import the DMABuf into a texture that we pass to GTK for rendering into the web view widget. If any of the required extensions is not available we can fallback to current platform dependent approach.

[Carlos Garcia Campos]

Pull request: https://github.com/WebKit/WebKit/pull/10726

[EWS]

Committed 262210@main (d2424c0fc67f): <https://commits.webkit.org/262210@main>

Reviewed commits have been landed. Closing PR #10726 and removing active labels.

[Diego Pino]

Re-opening for pull request https://github.com/webkit/webkit/pull/12153

[Diego Pino]

Ubuntu 20.04 post-commit bot is failing after this patch:

https://build.webkit.org/#/builders/595/builds/8868

```
/home/buildbot/worker/GTK-Linux-64-bit-Release-Ubuntu-2004-Build/build/Source/WebKit/WebProcess/glib/WebProcessGLib.cpp:128:9: error: ‘m_displayForCompositing’ was not declared in this scope
  128 |         m_displayForCompositing = WebCore::PlatformDisplayHeadless::create();
```

[EWS]

Committed 262405@main (84f510837198): <https://commits.webkit.org/262405@main>

Reviewed commits have been landed. Closing PR #12153 and removing active labels.

[gabriele balducci]

*** Bug 254976 has been marked as a duplicate of this bug. ***