[Threaded Compositor] Stop creating the GLContext on demand the first time makeContextCurrent is called

[Carlos Garcia Campos]

This is causing problems with animations when entering AC mode on demand. What happens is that the threaded compositor is created, then the animation is scheduled and during the first animation iteration the GLContext is created, making the first frame of the animation quite slow. In my computer creating the GLContext takes 0.8 seconds. If the animation duration is less than the time it takes to create the GLContext, the animation ends without iterating. This causing timeouts in the bots in tests like animations/animation-iteration-event-destroy-renderer.html that expect webkitAnimationIteration events that never fire.

[Carlos Garcia Campos]

Created attachment 299926 [details]
Patch

[Zan Dobersek]

Comment on attachment 299926 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=299926&action=review

> Source/WebKit2/Shared/CoordinatedGraphics/threadedcompositor/ThreadedCompositor.cpp:178
>      if (m_context)
>          return m_context->makeContextCurrent();

return m_context && m_context->makeContextCurrent();

[Carlos Garcia Campos]

Committed r211281: <http://trac.webkit.org/changeset/211281>