Add a timeout property to NavigateAction.

tools/telemetry/telemetry/page/actions/navigate.py

Index: tools/telemetry/telemetry/page/actions/navigate.py
diff --git a/tools/telemetry/telemetry/page/actions/navigate.py b/tools/telemetry/telemetry/page/actions/navigate.py
index 237278760982101a8bb82eb8b7fa3c1ef3c176b6..0762c7e9080447fa0ca768d97b7917b9716bb189 100644
--- a/tools/telemetry/telemetry/page/actions/navigate.py
+++ b/tools/telemetry/telemetry/page/actions/navigate.py
@@ -14,5 +14,10 @@ class NavigateAction(page_action.PageAction):
     else:
       target_side_url = page.url
 
-    tab.Navigate(target_side_url, page.script_to_evaluate_on_commit)
+    if hasattr(self, 'timeout_seconds') and self.timeout_seconds:
+      tab.Navigate(target_side_url,
+                   page.script_to_evaluate_on_commit,
+                   self.timeout_seconds)
+    else:
+      tab.Navigate(target_side_url, page.script_to_evaluate_on_commit)
     tab.WaitForDocumentReadyStateToBeInteractiveOrBetter()