* Simpler image cache API for clients to use.
* Significantly fewer threads.
* One thread for image cache task (multiplexes commands, decoder threads and async resource requests).
* 4 threads for decoder worker tasks.
* Removed ReflowEvent hacks in script and layout tasks.
* Image elements pass a Trusted<T> to image cache, which is used to dirty nodes via script task. Previous use of Untrusted addresses was unsafe.
* Image requests such as background-image on layout / paint threads trigger repaint only rather than full reflow.
* Add reflow batching for when multiple images load quickly.
* Reduces the number of paints loading wikipedia from ~95 to ~35.
* Reasonably simple to add proper prefetch support in a follow up PR.
* Async loaded images always construct Image fragments now, instead of generic.
* Image fragments support the image not being present.
* Simpler implementation of synchronous image loading for reftests.
* Removed image holder.
* image.onload support.
* image NaturalWidth and NaturalHeight support.
* Updated WPT expectations.
@jdm @ecoal95 I'm working on making VR happen in the Browser and I want to bring to Servo the [webVR APIs](https://github.com/MozVR/webvr-spec/blob/master/webvr.idl) we already have in Gecko. Before anything happens we need a working implementation of WebGL (and also the [fullscreen API](https://fullscreen.spec.whatwg.org/)). My implementation is very basic and probably naive (I just recently started to contribute to Servo). My patch is just a starting point:
- It only implements ```clearColor``` and ```clear``` methods of the [WebGL spec](https://www.khronos.org/registry/webgl/specs/latest/).
- It uses the readback strategy that ```canvasRenderingContext2D``` is using (The webgl task paints stuff independently on it's own buffer and the compositor task request the pixels back to the webgl task when it needs them) I'm sure there are much better ways to handle this. Latency and FPS are critical in VR so we have to figure out the fastest way to push pixels to the screen. I've read something about layerizing the canvas but I'm still not sure what that even means :)
- There's an included test you can try ```./mach run tests/ref/webgl-context/clearcolor.html```
@ecoal95 I know you'll be working on this for the next three months. With a foundation in place we will be able to make quick progress in parallel. This is exciting!
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This exposes another bug: "-0" failed to parse with str.parse(), and is now
successfully parsed into 0. However, input.size and textarea.{rows, cols} are
supposed to be "limited to only non-negative numbers greater than zero", so 0
is not actually supposed to be accepted.
This fixes a bug with elements with multiple class attributes. In this case,
the class attribute in the null namespace would only be considered if it was
the first class attribute in the list.
