autotest: replace scheduler uncaught exception spam with counter

BUG=None
TEST=None

Change-Id: If1ed4ce0f5bfa61ab6f198084d73a4895aaef84e
Reviewed-on: https://chromium-review.googlesource.com/489242
Commit-Ready: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Richard Barnette <jrbarnette@google.com>
diff --git a/scheduler/host_scheduler.py b/scheduler/host_scheduler.py
index 95b6b2a..d18aeaf 100755
--- a/scheduler/host_scheduler.py
+++ b/scheduler/host_scheduler.py
@@ -501,8 +501,7 @@
         # for host-scheduler role. Thus do not send email for it.
         raise
     except Exception:
-        email_manager.manager.log_stacktrace(
-                'Uncaught exception; terminating host_scheduler.')
+        metrics('%s/uncaught_exception' % _METRICS_PREFIX).increment()
         raise
     finally:
         email_manager.manager.send_queued_emails()
diff --git a/scheduler/monitor_db.py b/scheduler/monitor_db.py
index 6e7870a..7a8fad1 100755
--- a/scheduler/monitor_db.py
+++ b/scheduler/monitor_db.py
@@ -193,8 +193,8 @@
           # for scheduler role. Thus do not send email for it.
           logging.exception(e)
       except Exception:
-          email_manager.manager.log_stacktrace(
-              "Uncaught exception; terminating monitor_db")
+          metrics.Counter('chromeos/autotest/scheduler/uncaught_exception'
+                          ).increment()
 
     metadata_reporter.abort()
     email_manager.manager.send_queued_emails()