Allow multiple host pseudos in same compound.

Allow multiple host pseudos in same compound.

As part of optimizing away :host(-context) selectors which never may
match, we also skipped selectors with multiple :host(-context) pseudos
in the same compound.

Removed assert in findBestRuleSetAndAdd as that would now be required
to traverse the whole compound again to cover everything.

BUG=601585
Review URL: https://codereview.chromium.org/1872343002

Cr-Commit-Position: refs/heads/master@{#387263}
(cherry picked from commit fd7037ec2f171b5f917f90ece37ba20b4d8506ce)

Committed: https://chromium.googlesource.com/chromium/src/+/369818b67173d3ed4cbbc3af82fcb17a9a5528cf

[kochi, 2016-04-27 06:14:55]

Description was changed from

==========
Allow multiple host pseudos in same compound.

As part of optimizing away :host(-context) selectors which never may
match, we also skipped selectors with multiple :host(-context) pseudos
in the same compound.

Removed assert in findBestRuleSetAndAdd as that would now be required
to traverse the whole compound again to cover everything.

BUG=601585

Review URL: https://codereview.chromium.org/1872343002

Cr-Commit-Position: refs/heads/master@{#387263}
(cherry picked from commit fd7037ec2f171b5f917f90ece37ba20b4d8506ce)
==========

to

==========
Allow multiple host pseudos in same compound.

As part of optimizing away :host(-context) selectors which never may
match, we also skipped selectors with multiple :host(-context) pseudos
in the same compound.

Removed assert in findBestRuleSetAndAdd as that would now be required
to traverse the whole compound again to cover everything.

BUG=601585

Review URL: https://codereview.chromium.org/1872343002

Cr-Commit-Position: refs/heads/master@{#387263}
(cherry picked from commit fd7037ec2f171b5f917f90ece37ba20b4d8506ce)

Committed:
https://chromium.googlesource.com/chromium/src/+/369818b67173d3ed4cbbc3af82fc...
==========

[kochi, 2016-04-27 06:14:58]

Committed patchset #1 (id:1) manually as
369818b67173d3ed4cbbc3af82fcb17a9a5528cf.