Fix PathFilter constructor to be backward compatible with analyzer 0.26.0.

Fix PathFilter constructor to be backward compatible with analyzer 0.26.0.

Commit 24189ea4f965d8e018105fbbe9c727cea705e842 modified the
PathFilter constructor signature in a backwards-incompatible way, and
made corresponding changes to analysis_server, causing warnings to
show up in analysis_server when analyzed using the version of analyzer
in its pubspec.

This CL switches to a backwards-compatible signature and updates the
analyzer pubspec in preparation for publishing.  Once the new version
of analyzer is published I will update analysis_server's pubspec to
point to it, which should fix the warnings.

R=brianwilkerson@google.com

Committed: https://github.com/dart-lang/sdk/commit/d977370e3fac0e1a83cc3341367bfcb1f35407d2

[Paul Berry, 2015-08-06 17:22:21]

paulberry@google.com changed reviewers:
+ brianwilkerson@google.com

[Brian Wilkerson, 2015-08-06 17:25:49]

LGTM

[Paul Berry, 2015-08-06 18:04:14]

Committed patchset #1 (id:1) manually as
d977370e3fac0e1a83cc3341367bfcb1f35407d2 (presubmit successful).