Modular pipelines

[tikue]

When loading pages, the constellation spawns a new script<-->layout<-->renderer pipeline that loads in the background while scripts continue executing on the currently loaded page.

[tikue]

r? pcwalton

[pcwalton]

As I mentioned before, Constellation should probably be renamed Browser (other name suggestions welcome), at least in the context of the task, because the Browser task handles all constellations.

[tikue]

Yes, I agree, but I think the current implementation actually only represents a single constellation. In other words, the browser does not yet exist, because we don't have multiple tabs and windows yet.

[metajack]

r+

[metajack]

The code looks good.

I had one issue that I think you can resolve in a future PR. Currently a non-copyable token is given to the renderer to allow it to send paint messages. However, this token is never used. Instead, the paint message sends an id which is not tied to the token at all.

The renderer should have to send the token with the paint message, or something derived from the token, otherwise, we might as well use a boolean piece of state and just have messages that indicate only the state changes.

[bors-servo]

saw approval from metajack
at tikue@6f7107e

[bors-servo]

merging tkuehn/servo/master = 6f7107e into auto

[bors-servo]

tkuehn/servo/master = 6f7107e merged ok, testing candidate = 213d9a0

[bors-servo]

all tests pass:
http://servo-buildbot.pub.build.mozilla.org/builders/linux/builds/97
http://servo-buildbot.pub.build.mozilla.org/builders/mac/builds/51

[bors-servo]

fast-forwarding master to auto = 213d9a0