Fixed conflict
Fixed merge issue
Finished implementation
Disable tinyfiledialogs on Windows
addressed comments
Use ancestor's SubpageId
Move display alert from method to function
Add extra test for nested iframes
Addressed comments
Updated tinyfiledialogs
This allows keeping the VertexAttrib* calls asynchronous.
Another option would be to do the validation in the apply() function,
but that'd require us passing an unnecessary channel around and add
extra synchronization.
The counterpart of this is that it has to be updated when the context
changes, but that's less problem.
This changes headless operation to strictly be a runtime option, rather
than a compile-time one. Note that the old headless version still relied
on a display server to support WebGL, while it now requires one all the
time.
Fixes#8573
Also change when pipelines become active.
This makes the constellation activate a pipeline as the current frame
when it is ready to do initial reflow, rather than when it is ready
to paint.
This fixes a number of intermittent failures that could previously occur
if an iframe was not visible - which would mean it was never moved from
a pending frame in the constellation to an active frame.
(It happens that webrender exposes these intermittents as permanent failures).
