checkdeps: Fix documentation for include_rules.

The example in the documentation used '{ }' instead of '[ ]' to
define a list. I actually created a new DEPS file with this erroneous
convention, and checkdeps worked on Linux, but failed on Windows with
an enigmatic "syntax error" message :-)

Probably explained by the following explanation from torne@:
  On Python 2.7 the syntax {"foo", "bar"} with the values omitted
  creates a set, rather than a dictionary (this was backported from
  Python 3). Linux machines likely have 2.7. On earlier Pythons this
  is a syntax error, as you saw. I think the Python we bundle in
  depot_tools to use on windows is still 2.6?

BUG=

Review URL: https://codereview.chromium.org/27485011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229350 0039d316-1c4b-4281-b951-d872f2087c98
Android perf tests: only store the retry results if it's better.

Rather than blindingly store the results of the latest perf test,
keep the "least worst" run.

BUG=

Review URL: https://codereview.chromium.org/27502002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229351 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229351