Reland [telemetry] Timeline model cleanups

Reland [telemetry] Timeline model cleanups

Previously reviewed at https://chromiumcodereview.appspot.com/19772005

R=achuith@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=213228

[nduca, 2013-07-19 18:31:01]

Hey Ahuith, Simran - 

I've fixed the patch so its landable but the cros failures I hit on this patch
the first time round were really puzzling to me. 

Any advice on those errors before I land this again?

[tonyg, 2013-07-19 18:40:25]

Can you call out what changed from the previous version in the change
description? Also, I assume the image_decoding measurement is happy in addition
to the unittests?

[nduca, 2013-07-19 18:49:01]

It was actually silly. I made a last second change based on review feedback:

   def IterEventsInThisContainer(self):
-    itertools.chain(
+    return itertools.chain(
       iter(self._open_slices),
       iter(self._newly_added_slices),
-      self.IterAllAsyncSlices,
-      self.IterAllSlices,
+      self.IterAllAsyncSlices(),
+      self.IterAllSlices(),
       iter(self._samples)
       )


There's also likely an issue with the ebuild/autotest integration of telemetry
that was causing cros bots to fail. @sbasi is helping me to understand that.

[nduca, 2013-07-19 18:51:13]

(and yep, image decoding should be fine)

[tonyg, 2013-07-19 19:47:34]

lgtm (based on previous real review)

[commit-bot: I haz the power, 2013-07-23 18:26:24]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nduca@chromium.org/19790005/1

[commit-bot: I haz the power, 2013-07-23 21:29:56]

Change committed as 213228