Rename isolate_dependency_tracked to files.

Rename isolate_dependency_tracked to files.

That's the new name, and the next swarming_client roll will refuse the old name.

R=jshin@chromium.org
BUG=

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=292317

[M-A Ruel, 2014-10-02 22:19:14]

Another issue I saw is that third_party/icu in src/DEPS is not at ToT, so the
next roll will roll r292144 and r292131, since it's currently syncing at 292003.

[jungshik at Google, 2014-10-03 23:53:35]

On 2014/10/02 22:19:14, M-A Ruel wrote:
> Another issue I saw is that third_party/icu in src/DEPS is not at ToT, so the
> next roll will roll r292144 and r292131, since it's currently syncing at
292003.

LGTM 

Yeah, I wanted to lump two changes in a single DEPS roll. If you want to roll to
this revision (with your CL), go ahead. I can quickly follow that up with next
one.

[M-A Ruel, 2014-10-04 00:00:49]

Committed patchset #1 (id:1) manually as r292317 (presubmit successful).