cairo-gl can be built with full OpenGL support or with OpenGLESv2 support.
When cairo-gl is built with only OpenGLESv2 support, cairo-glx is not enabled.
If then webkitgtk+ is built with GLX (full OpenGL) support and with it ACCELERATED_2D_CANVAS support the following build error would happen:
Source/WebCore/platform/graphics/glx/GLContextGLX.cpp:270:74: error: 'cairo_glx_device_create' was not declared in this scope
make: *** [Source/WebCore/CMakeFiles/WebCorePlatformGTK.dir/platform/graphics/glx/GLContextGLX.cpp.o] Error 1
Created attachment 261217 [details]
Comment on attachment 261217 [details]
Clearing flags on attachment: 261217
Committed r189826: <http://trac.webkit.org/changeset/189826>
All reviewed patches have been landed. Closing bug.