Add support for python pageset

tools/telemetry/telemetry/page/actions/wait.py

Index: tools/telemetry/telemetry/page/actions/wait.py
diff --git a/tools/telemetry/telemetry/page/actions/wait.py b/tools/telemetry/telemetry/page/actions/wait.py
index 4cb8742f267be96fd298c2d7a62128d489acc596..d2c8073ef69dfb95e25542c1154fdfd7e1c950d8 100644
--- a/tools/telemetry/telemetry/page/actions/wait.py
+++ b/tools/telemetry/telemetry/page/actions/wait.py
@@ -18,6 +18,22 @@ class WaitAction(page_action.PageAction):
     return (getattr(self, 'condition', None) == 'navigate' or
             getattr(self, 'condition', None) == 'href_change')
 
+  def UntilTrue(self, expression):

[nduca, 2014/03/05 03:00:57]

I think in the long term,  I'd rather we remove these and switch the page to
call stuff like:

action_runner.WaitUntilTrue(...)

And then this file ends up exporting just a bunch of WaitUntil* methods, and
action_runner has a bunch of very simple WaitUntil methods that call into this
module.

Point being, I dont think there's any need for actions to have state, in the
end, except as functions.

As such, for the very very near term, lets just make actions work as they do,
meaning the python page set is going to be a bit ugly and have to make various
dicts... on the assumpiton that we'll do a followup to move the action runner to
be functions.

Wdyt?

[nednguyen, 2014/03/05 04:54:04]

sgtm :)

+    self.SetAttributes({'javascript': expression})
+    return self
+
+  def UntilTextElementAvailable(self, text):
+    self.SetAttributes({'condition': 'element', 'text': text})
+    return self
+
+  def UntilSelectorElementAvailable(self, selector):
+    self.SetAttributes({'condition': 'element', 'selector': selector})
+    return self
+
+  def ForSeconds(self, seconds):
+    self.SetAttributes({'seconds': seconds})
+    return self
+
   def RunAction(self, page, tab, previous_action):
     tab.ExecuteJavaScript(
         'console.time("' + self._GetUniqueTimelineMarkerName() + '")')