[pinpoint] Add trace links.

dashboard/dashboard/pinpoint/models/quest/read_value.py

Index: dashboard/dashboard/pinpoint/models/quest/read_value.py
diff --git a/dashboard/dashboard/pinpoint/models/quest/read_value.py b/dashboard/dashboard/pinpoint/models/quest/read_value.py
index 090ff45e2b1513ff4f5939b78b36c0d09cedff7d..e2ae829cbab0740ccdcc0c1b2bbd0211560dc34b 100644
--- a/dashboard/dashboard/pinpoint/models/quest/read_value.py
+++ b/dashboard/dashboard/pinpoint/models/quest/read_value.py
@@ -42,11 +42,15 @@ class _ReadChartJsonValueExecution(execution.Execution):
     super(_ReadChartJsonValueExecution, self).__init__()
     self._chart = chart
     self._tir_label = tir_label
-    self._trace = trace or 'summary'
+    self._trace = trace
     self._isolate_hash = isolate_hash
 
+    self._trace_url = None
+
   def _AsDict(self):
-    return {}
+    if not self._trace_url:

[shatch, 2017/09/27 11:55:50]

Getting a failure here with no attribute _trace_url on old data. Should include
some migration in this cl.

+      return {}
+    return {'trace_url': self._trace_url}
 
   def _Poll(self):
     chartjson = _RetrieveOutputJson(self._isolate_hash, 'chartjson-output.json')
@@ -56,13 +60,13 @@ class _ReadChartJsonValueExecution(execution.Execution):
     else:
       chart_name = self._chart
     if chart_name not in chartjson['charts']:
-      raise ReadValueError('The chart "%s" is not in the results.' %
-                           chart_name)
-    if self._trace not in chartjson['charts'][chart_name]:
-      raise ReadValueError('The trace "%s" is not in the results.' %
-                           self._trace)
-    chart = chartjson['charts'][chart_name][self._trace]
+      raise ReadValueError('The chart "%s" is not in the results.' % chart_name)
 
+    trace_name = self._trace or 'summary'
+    if trace_name not in chartjson['charts'][chart_name]:
+      raise ReadValueError('The trace "%s" is not in the results.' % trace_name)
+
+    chart = chartjson['charts'][chart_name][trace_name]
     if chart['type'] == 'list_of_scalar_values':
       result_values = chart['values']
     elif chart['type'] == 'histogram':
@@ -70,6 +74,9 @@ class _ReadChartJsonValueExecution(execution.Execution):
     elif chart['type'] == 'scalar':
       result_values = [chart['value']]
 
+    if self._trace:

[shatch, 2017/09/27 11:55:50]

The bug linked (technically the one duped and closed) is for surfacing all the
trace links for perf try jobs, but this looks like it'll only surface a single
trace link?

[perezju, 2017/09/27 12:24:06]

chartjson (I think) only keeps a link to one of the traces. :(

And, in most cases, since we're using --pageset-repeat 1 this should be OK (I
think).

And this shouldn't be an issue when we move to proper histograms.

+      self._trace_url = chartjson['charts']['trace'][self._trace]['cloud_url']
+
     self._Complete(result_values=tuple(result_values))