[test] Report more test duration data.

This will allow the infrastructure to warn about new very
slow tests which are not marked as slow. If not marked, they
might be scheduled late in the test run and prolong the
overall running time uselessly.

BUG=chromium:601468
LOG=n

Review URL: https://codereview.chromium.org/1863793005

Cr-Commit-Position: refs/heads/master@{#35356}

tools/testrunner/local/progress.py

@@ -34,6 +34,7 @@ import time
 
 from . import execution
 from . import junit_output
+from . import statusfile
 
 
 ABS_PATH_PREFIX = os.getcwd() + os.sep
@@ -329,6 +330,12 @@ class JsonTestProgressIndicator(ProgressIndicator):
         # Buildbot might start out with an empty file.
         complete_results = json.loads(f.read() or "[]")
 
+    duration_mean = None
+    if self.tests:
+      # Get duration mean.
+      duration_mean = (
+          sum(t.duration for t in self.tests) / float(len(self.tests)))
+
     # Sort tests by duration.
     timed_tests = [t for t in self.tests if t.duration is not None]
     timed_tests.sort(lambda a, b: cmp(b.duration, a.duration))
@@ -338,6 +345,7 @@ class JsonTestProgressIndicator(ProgressIndicator):
         "flags": test.flags,
         "command": self._EscapeCommand(test).replace(ABS_PATH_PREFIX, ""),
         "duration": test.duration,
+        "marked_slow": statusfile.IsSlow(test.outcomes),
       } for test in timed_tests[:20]
     ]
 
@@ -346,6 +354,8 @@ class JsonTestProgressIndicator(ProgressIndicator):
       "mode": self.mode,
       "results": self.results,
       "slowest_tests": slowest_tests,
+      "duration_mean": duration_mean,
+      "test_total": len(self.tests),
     })
 
     with open(self.json_test_results, "w") as f: