Add documentation about the scrolling model
Make sure reftests aren't passing because nothing == nothing

In the test harness, assert that the two images aren't all white.

Fixes #3481
try to reset flows which need reflow, since reflow isn't yet idempotent
auto merge of #3634 : mrobinson/servo/scrolling-doc, r=jdm
layout: Introduce support for legacy presentational attributes to selector
matching, and use it for `<input size>` and `<td width>`.

This implements a general framework for legacy presentational attributes
to the DOM and style calculation, so that adding more of them later will
be straightforward.
auto merge of #3622 : pcwalton/servo/html4ever, r=jdm

This implements a general framework for legacy presentational attributes
to the DOM and style calculation, so that adding more of them later will
be straightforward.
auto merge of #3645 : gilles-leblanc/servo/issue-3481, r=kmcallister

In the test harness, assert that the two images aren't all white.

Fixes #3481
layout: Rewrite intrinsic inline-size and automatic table layout to
match L. David Baron's work-in-progress specification.

    http://dbaron.org/css/intrinsic/

Column spans are not yet supported.

This effectively adds support for percentage widths, and it also fixes
many bugs, improving the layout of Google and Wikipedia.
Implement media queries parser and matching. Improves mobile first sites like bootstrap3.
auto merge of #3609 : pcwalton/servo/tables, r=SimonSapin

http://dbaron.org/css/intrinsic/

Column spans are not yet supported.

This effectively adds support for percentage widths, and it also fixes
many bugs, improving the layout of Google and Wikipedia.

r? @SimonSapin
auto merge of #3640 : cgaebel/servo/incremental-flow-construction, r=pcwalton

This also hides the not-yet-working parts of incremental reflow behind a runtime
flag. As I get the failing reftests passing, I'll send pull requests for them one
by one.
Removes duplicate CSS selector matching logic.

Now that DOM/Flow traversals have been refactored out, the `recalc_style_for_subtree`
function in `css/matching.rs` can be removed, in lieu of just running the standard
`recalc_style_for_node` and `construct_flows` traversals sequentially. Now we
no longer have the maintenance headache of duplicating selector matching logic
in two places! \o/

r? @pcwalton
auto merge of #3610 : glennw/servo/media-queries, r=SimonSapin
auto merge of #3668 : cgaebel/servo/sequential-reflow, r=pcwalton

Now that DOM/Flow traversals have been refactored out, the `recalc_style_for_subtree`
function in `css/matching.rs` can be removed, in lieu of just running the standard
`recalc_style_for_node` and `construct_flows` traversals sequentially. Now we
no longer have the maintenance headache of duplicating selector matching logic
in two places! \o/

This passes reftests with both default arguments, and with `-y 1`.

r? @pcwalton
Add DOMRefCell<T> for safe borrowing in layout.
Use DOMRefCell<T> in element.rs.
fixup! Use DOMRefCell<T> in element.rs.
Revert "fixup! Use DOMRefCell<T> in element.rs."

This reverts commit 145338fd94abc39ae6eb695dc5c5ef1712db516e.
Revert "Use DOMRefCell<T> in element.rs."

This reverts commit d1ae985322e6de6d0212012af142ad19eb6415da.
Revert "Add DOMRefCell<T> for safe borrowing in layout."

This reverts commit b095ab3fbc354846a1a7148890c4ab1933708017.