Add compiler info to experiment data.

Check the build label to see which compiler was used.  Store the
compiler in the label, and add it to the json filename
and output.

Also update nightly buildbot script to add 'compiler' field to
labels.

BUG=None
TEST=Tested in my directory.

Change-Id: I124c4910cce1145708bb2a52e3a6d6dff93777c3
Reviewed-on: https://chrome-internal-review.googlesource.com/231811
Commit-Ready: Caroline Tice <cmtice@google.com>
Tested-by: Caroline Tice <cmtice@google.com>
Reviewed-by: Caroline Tice <cmtice@google.com>
diff --git a/crosperf/experiment.py b/crosperf/experiment.py
index e18556a..f9f8fb5 100644
--- a/crosperf/experiment.py
+++ b/crosperf/experiment.py
@@ -92,10 +92,10 @@
     self._internal_counter_lock = Lock()
 
   def set_schedv2(self, schedv2):
-      self._schedv2 = schedv2
+    self._schedv2 = schedv2
 
   def schedv2(self):
-      return self._schedv2
+    return self._schedv2
 
   def _GenerateBenchmarkRuns(self):
     """Generate benchmark runs from labels and benchmark defintions."""