Improve performance tags display - percent and sorting.

Improve performance tags display - percent and sorting.

R=paulberry@google.com
BUG=

Committed: https://code.google.com/p/dart/source/detail?r=43992

[Paul Berry, 2015-02-24 17:45:22]

lgtm once comment is addressed.

https://codereview.chromium.org/953933002/diff/1/pkg/analysis_server/lib/src/...
File pkg/analysis_server/lib/src/get_handler.dart (right):

https://codereview.chromium.org/953933002/diff/1/pkg/analysis_server/lib/src/...
pkg/analysis_server/lib/src/get_handler.dart:292: int percent = (tag.elapsedMs *
100) ~/ totalTime;
This will round down to percent granularity.  I don't think that's high enough
resolution--sometimes the difference between 1.01% and 1.99% is significant.

How about if we print two significant figures after the decimal point, like
observatory does?

[scheglov, 2015-02-24 17:53:15]

Committed patchset #2 (id:20001) manually as 43992 (presubmit successful).