Add a snapshot of flutter/engine/src/build to our sdk

build/android/pylib/instrumentation/json_perf_parser.py

Index: build/android/pylib/instrumentation/json_perf_parser.py
diff --git a/build/android/pylib/instrumentation/json_perf_parser.py b/build/android/pylib/instrumentation/json_perf_parser.py
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+++ b/build/android/pylib/instrumentation/json_perf_parser.py
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+# Copyright 2013 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.
+
+
+"""A helper module for parsing JSON objects from perf tests results."""
+
+import json
+
+
+def GetAverageRunInfo(json_data, name):
+  """Summarizes TraceEvent JSON data for performance metrics.
+
+  Example JSON Inputs (More tags can be added but these are required):
+  Measuring Duration:
+  [
+    { "cat": "Java",
+      "ts": 10000000000,
+      "ph": "S",
+      "name": "TestTrace"
+    },
+    { "cat": "Java",
+      "ts": 10000004000,
+      "ph": "F",
+      "name": "TestTrace"
+    },
+    ...
+  ]
+
+  Measuring Call Frequency (FPS):
+  [
+    { "cat": "Java",
+      "ts": 10000000000,
+      "ph": "I",
+      "name": "TestTraceFPS"
+    },
+    { "cat": "Java",
+      "ts": 10000004000,
+      "ph": "I",
+      "name": "TestTraceFPS"
+    },
+    ...
+  ]
+
+  Args:
+    json_data: A list of dictonaries each representing a JSON object.
+    name: The 'name' tag to filter on in the JSON file.
+
+  Returns:
+    A dictionary of result data with the following tags:
+      min: The minimum value tracked.
+      max: The maximum value tracked.
+      average: The average of all the values tracked.
+      count: The number of times the category/name pair was tracked.
+      type: The type of tracking ('Instant' for instant tags and 'Span' for
+            begin/end tags.
+      category: The passed in category filter.
+      name: The passed in name filter.
+      data_points: A list of all of the times used to generate this data.
+      units: The units for the values being reported.
+
+  Raises:
+    Exception: if entry contains invalid data.
+  """
+
+  def EntryFilter(entry):
+    return entry['cat'] == 'Java' and entry['name'] == name
+  filtered_entries = filter(EntryFilter, json_data)
+
+  result = {}
+
+  result['min'] = -1
+  result['max'] = -1
+  result['average'] = 0
+  result['count'] = 0
+  result['type'] = 'Unknown'
+  result['category'] = 'Java'
+  result['name'] = name
+  result['data_points'] = []
+  result['units'] = ''
+
+  total_sum = 0
+
+  last_val = 0
+  val_type = None
+  for entry in filtered_entries:
+    if not val_type:
+      if 'mem' in entry:
+        val_type = 'mem'
+
+        def GetVal(entry):
+          return entry['mem']
+
+        result['units'] = 'kb'
+      elif 'ts' in entry:
+        val_type = 'ts'
+
+        def GetVal(entry):
+          return float(entry['ts']) / 1000.0
+
+        result['units'] = 'ms'
+      else:
+        raise Exception('Entry did not contain valid value info: %s' % entry)
+
+    if not val_type in entry:
+      raise Exception('Entry did not contain expected value type "%s" '
+                      'information: %s' % (val_type, entry))
+    val = GetVal(entry)
+    if (entry['ph'] == 'S' and
+        (result['type'] == 'Unknown' or result['type'] == 'Span')):
+      result['type'] = 'Span'
+      last_val = val
+    elif ((entry['ph'] == 'F' and result['type'] == 'Span') or
+          (entry['ph'] == 'I' and (result['type'] == 'Unknown' or
+                                   result['type'] == 'Instant'))):
+      if last_val > 0:
+        delta = val - last_val
+        if result['min'] == -1 or result['min'] > delta:
+          result['min'] = delta
+        if result['max'] == -1 or result['max'] < delta:
+          result['max'] = delta
+        total_sum += delta
+        result['count'] += 1
+        result['data_points'].append(delta)
+      if entry['ph'] == 'I':
+        result['type'] = 'Instant'
+        last_val = val
+  if result['count'] > 0:
+    result['average'] = total_sum / result['count']
+
+  return result
+
+
+def GetAverageRunInfoFromJSONString(json_string, name):
+  """Returns the results from GetAverageRunInfo using a JSON string.
+
+  Args:
+    json_string: The string containing JSON.
+    name: The 'name' tag to filter on in the JSON file.
+
+  Returns:
+    See GetAverageRunInfo Returns section.
+  """
+  return GetAverageRunInfo(json.loads(json_string), name)
+
+
+def GetAverageRunInfoFromFile(json_file, name):
+  """Returns the results from GetAverageRunInfo using a JSON file.
+
+  Args:
+    json_file: The path to a JSON file.
+    name: The 'name' tag to filter on in the JSON file.
+
+  Returns:
+    See GetAverageRunInfo Returns section.
+  """
+  with open(json_file, 'r') as f:
+    data = f.read()
+    perf = json.loads(data)
+
+  return GetAverageRunInfo(perf, name)