tools: Add a tool to load pages on a device, and pull the predictor database.

tools/android/loading/devtools_monitor.py

Index: tools/android/loading/devtools_monitor.py
diff --git a/tools/android/loading/devtools_monitor.py b/tools/android/loading/devtools_monitor.py
index cd52dfba7f57d00b6e5cd4fe4a0e6cdb49e906fb..b64e468d5c210c447c8cd7178214f27413e93382 100644
--- a/tools/android/loading/devtools_monitor.py
+++ b/tools/android/loading/devtools_monitor.py
@@ -235,9 +235,9 @@ class DevToolsConnection(object):
     Args:
       url: (str) a URL to navigate to before starting monitoring loop.
       timeout_seconds: timeout in seconds for monitoring loop.
-      stop_delay_multiplier: How long to wait after page load completed before
-        tearing down, relative to the time it took to reach the page load to
-        complete.
+      stop_delay_multiplier: (float) How long to wait after page load completed
+        before tearing down, relative to the time it took to reach the page load
+        to complete.
     """
     for domain in self._domains_to_enable:
       self._ws.RegisterDomain(domain, self._OnDataReceived)
@@ -271,11 +271,13 @@ class DevToolsConnection(object):
     elif self._monitoring_stop_timestamp is None:
       assert self._monitoring_start_timestamp is not None
       current_time = datetime.datetime.now()
-      stop_delay_duration = self._stop_delay_multiplier * (
-          current_time - self._monitoring_start_timestamp)
-      logging.info('Delaying monitoring stop for %ds',
-                   stop_delay_duration.total_seconds())
-      self._monitoring_stop_timestamp = current_time + stop_delay_duration
+      stop_delay_duration_seconds = self._stop_delay_multiplier * (
+          current_time - self._monitoring_start_timestamp).seconds

[pasko, 2016/11/14 13:21:27]

was it also assuming seconds before or something more fine-granular?

it it is rounded to seconds now, it might affect hypothetical noise to
hypothetical sandwich runs. WDYT?

[Benoit L, 2016/11/14 13:26:19]

It was seconds as well, but couldn't handle non-integer scaling factors.

+      logging.info('Delaying monitoring stop for %.1fs',
+                   stop_delay_duration_seconds)
+      self._monitoring_stop_timestamp = (
+          current_time + datetime.timedelta(
+              seconds=stop_delay_duration_seconds))
 
   def ExecuteJavaScript(self, expression):
     """Run JavaScript expression.