mojo_benchmark: improve recording the chart data for perf dashboard.

mojo/devtools/common/devtoolslib/perf_dashboard_unittest.py

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """Tests for the Chromium Performance Dashboard data format implementation."""
 
 import imp
 import json
 import os.path
 import sys
 import unittest
 
 try:
   imp.find_module("devtoolslib")
 except ImportError:
   sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
 from devtoolslib.perf_dashboard import ChartDataRecorder
 
+
 class ChartDataRecorderTest(unittest.TestCase):
   """Tests the chart data recorder."""
 
   def test_empty(self):
     """Tests chart data with no charts."""
-    recorder = ChartDataRecorder()
+    recorder = ChartDataRecorder('benchmark')
     result = json.loads(recorder.get_json())
-    self.assertEquals(0, len(result))
+    self.assertEquals({
+        'format_version': '1.0',
+        'benchmark_name': 'benchmark',
+        'charts': {}}, result)
 
   def test_one_chart(self):
     """Tests chart data with two samples in one chart."""
-    recorder = ChartDataRecorder()
+    recorder = ChartDataRecorder('benchmark')
     recorder.record_scalar('chart', 'val1', 'ms', 1)
     recorder.record_scalar('chart', 'val2', 'ms', 2)
 
     result = json.loads(recorder.get_json())
-    self.assertEquals(1, len(result))
-    self.assertEquals(2, len(result['chart']))
+    self.assertEquals('1.0', result['format_version'])
+    self.assertEquals('benchmark', result['benchmark_name'])
+
+    charts = result['charts']
+    self.assertEquals(1, len(charts))
+    self.assertEquals(2, len(charts['chart']))
     self.assertEquals({
         'type': 'scalar',
         'name': 'val1',
         'units': 'ms',
-        'value': 1}, result['chart'][0])
+        'value': 1}, charts['chart'][0])
     self.assertEquals({
         'type': 'scalar',
         'name': 'val2',
         'units': 'ms',
-        'value': 2}, result['chart'][1])
+        'value': 2}, charts['chart'][1])
 
   def test_two_charts(self):
     """Tests chart data with two samples over two charts."""
-    recorder = ChartDataRecorder()
+    recorder = ChartDataRecorder('benchmark')
     recorder.record_scalar('chart1', 'val1', 'ms', 1)
     recorder.record_scalar('chart2', 'val2', 'ms', 2)
 
     result = json.loads(recorder.get_json())
-    self.assertEquals(2, len(result))
-    self.assertEquals(1, len(result['chart1']))
+    self.assertEquals('1.0', result['format_version'])
+    self.assertEquals('benchmark', result['benchmark_name'])
+
+    charts = result['charts']
+    self.assertEquals(2, len(charts))
+    self.assertEquals(1, len(charts['chart1']))
     self.assertEquals({
         'type': 'scalar',
         'name': 'val1',
         'units': 'ms',
-        'value': 1}, result['chart1'][0])
-    self.assertEquals(1, len(result['chart2']))
+        'value': 1}, charts['chart1'][0])
+    self.assertEquals(1, len(charts['chart2']))
     self.assertEquals({
         'type': 'scalar',
         'name': 'val2',
         'units': 'ms',
-        'value': 2}, result['chart2'][0])
+        'value': 2}, charts['chart2'][0])