Fix redraw of WPT UI output, and slightly improve line counting
See discussion in PR #8551.
Redraw of the first test name was broken due to a mix-up between two ANSI escape codes.
I also took the opportunity to change the way line count is calculated. It's a bit cleaner that way (the new operation is ~%20 faster, but that's unnoticeable).
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/8861)
<!-- Reviewable:end -->
M1504: Implement basic support for withCredentials API
The pull request includes the following task:
* Implemented basic network-level support by adding a member to LoadData that is used by http_loader.rs to conditionally exclude cookies from the HTTP request if the flag is false (default true)
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/8812)
<!-- Reviewable:end -->
M1503 : Integrate XML Parser : First 2 of 4 Subsequent Steps
Rebase of #8746. Introduce and use an XML parser for text/xml network responses when loading web pages.
webgl: Fix texturing
These two tiny changes were making WebGL textures not work.
It was not seen in our texturing test since it only used one texture,
we render to a texture by default, and that texture was bound to
`gl::TEXTURE_2D`.
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/8788)
<!-- Reviewable:end -->
fix intermittent Option::unwrap in timers
fixes intermittent #8616
This intermittent indicates real problem in code.
Lets consider such code:
```javascript
// timer 1
setTimeout(function() {
//timer 2
setTimeout(function() {}, 0);
}, 0);
```
When we receive event to fire timer 1 it will be selected and extracted from active timers list in fire_timer function. During timer 1 handler execution we will schedule timer 2 and request timer event for it. But it will be executed during same fire_timer call because of 0 timeout. And as a result we will have empty timers list and expecting event for timer 2 that will crash in assert.
I'm not sure that all I've written is clear, but we have something like this:
```
install timer 1 -> [1] in timers list
push and expect timer event 1 -> expected_event=1
received timer event 1
fire_timer()
select timer 1 to execute -> [] in timers list
execute timer 1 handler
install timer 2 -> [2] in timers list
push and expect timer event 2 -> expected_event=2
select timer 2 to execute (because of 0 timeout) -> [] in tiemrs list
execute timer 2 handler
expected_event=2 is dangling
received timer event 2
fire_timer() -> BOOM
```
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/8768)
<!-- Reviewable:end -->
The validations performed in the script side of this should always
prevent this from happening, and this will allow us to catch bugs like
the previous one.
Allow `./mach build` to enable Servo's headless mode
As mentioned in #7512 and #7637, the environment variable SERVO_HEADLESS
enables building the OSMesa version of Servo when it is set to 1.
Instead, this should be a command line option to mach's build command.
Fixes#7637.
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/7734)
<!-- Reviewable:end -->
Add slow path for hit testing of iframe behind positioned content layer
Fixes browser.html blocker #8759. r? @pcwalton
This adds a slow path for cases where the compositor's layer-based hit testing is incorrect. If the script task discovers that a mouse event should have been dispatched to an iframe, it bounces the event back to the constellation to be forwarded to the correct pipeline.
This isn't terribly slow (on the slow path, it adds one extra round-trip message between script and constellation), but if we want to optimize this better we could instead replace the compositor's layer hit testing with display list hit testing in the paint task. This would be a more complicated change that I think we should save for a follow-up.
This only fixes mouse input for now. A basically-identical change will be needed for touch-screen input, whether we stick with this approach or switch to the paint task.
<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/servo/servo/8785)
<!-- Reviewable:end -->
Fixes#8759.
This adds a slow path for cases where the compositor's layer-based hit testing
is incorrect. To optimize for this case, we could instead replace the
layer hit testing with display-list hit testing done in the paint task.
