Refactor BenchmarkResult.Add to take enum for data_type

tools/telemetry/telemetry/page/buildbot_page_measurement_results.py

Index: tools/telemetry/telemetry/page/buildbot_page_measurement_results.py
===================================================================
--- tools/telemetry/telemetry/page/buildbot_page_measurement_results.py	(revision 217866)
+++ tools/telemetry/telemetry/page/buildbot_page_measurement_results.py	(working copy)
@@ -7,6 +7,7 @@
 
 from telemetry.page import page_measurement_results
 from telemetry.page import perf_tests_helper
+from telemetry.page import result_data_type
 
 class BuildbotPageMeasurementResults(
     page_measurement_results.PageMeasurementResults):
@@ -15,7 +16,7 @@
     self._trace_tag = trace_tag
 
   def _PrintPerfResult(self, measurement, trace, values, units,
-                       result_type='default'):
+                       result_type=result_data_type.DEFAULT):
     perf_tests_helper.PrintPerfResult(
         measurement, trace, values, units, result_type)
 
@@ -64,11 +65,11 @@
         results_summary.iteritems()):
       measurement, units, data_type = measurement_units_type
 
-      if 'histogram' in data_type:
-        by_url_data_type = 'unimportant-histogram'
+      if result_data_type.IsHistogram(data_type):
+        by_url_data_type = result_data_type.UNIMPORTANT_HISTOGRAM
       else:
-        by_url_data_type = 'unimportant'
-      if '.' in measurement and 'histogram' not in data_type:
+        by_url_data_type = result_data_type.UNIMPORTANT
+      if '.' in measurement and not result_data_type.IsHistogram(data_type):
         measurement, trace = measurement.split('.', 1)
         trace += self._trace_tag
       else:
@@ -80,7 +81,7 @@
           ((self.errors or self.failures) and len(value_url_list) == 1)):
         url_value_map = defaultdict(list)
         for value, url in value_url_list:
-          if 'histogram' in data_type and url_value_map[url]:
+          if result_data_type.IsHistogram(data_type) and url_value_map[url]:
             # TODO(tonyg/marja): The histogram processing code only accepts one
             # histogram, so we only report the first histogram. Once histograms
             # support aggregating multiple values, this can be removed.
@@ -96,7 +97,8 @@
       # For histograms, we don't print the average data, only the _by_url,
       # unless there is only 1 page in which case the _by_urls are omitted.
       if not (self.errors or self.failures):
-        if 'histogram' not in data_type or len(value_url_list) == 1:
+        if (not result_data_type.IsHistogram(data_type) or
+            len(value_url_list) == 1):
           values = [i[0] for i in value_url_list]
           if isinstance(values[0], list):
             values = list(chain.from_iterable(values))