[Telemetry] Change trace_data to hold a list of raw trace data for each trace part

telemetry/telemetry/internal/backends/chrome_inspector/tracing_backend.py

 # 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.
 
 import json
 import logging
 import socket
 import time
 import traceback
 
@@ skipping 253 matching lines @@
           raise TracingTimeoutException(
               'Only received partial trace data due to timeout after %s '
               'seconds. If the trace data is big, you may want to increase '
               'the timeout amount.' % elapsed_time)
     finally:
       self._trace_data_builder = None
 
   def _NotificationHandler(self, res):
     if 'Tracing.dataCollected' == res.get('method'):
       value = res.get('params', {}).get('value')
-      self._trace_data_builder.AddEventsTo(
+      self._trace_data_builder.AddTraceFor(
         trace_data_module.CHROME_TRACE_PART, value)
     elif 'Tracing.tracingComplete' == res.get('method'):
       stream_handle = res.get('params', {}).get('stream')
       if not stream_handle:
         self._has_received_all_tracing_data = True
         return
       reader = _DevToolsStreamReader(self._inspector_websocket, stream_handle)
       reader.Read(self._ReceivedAllTraceDataFromStream)
 
   def _ReceivedAllTraceDataFromStream(self, data):
+    # For now we still unpack trace data to dictionary form.
     trace = json.loads(data)
-    if type(trace) == dict:
-      for part in trace_data_module.ALL_TRACE_PARTS:
-        field_name = part.raw_field_name
-        if field_name in trace:
-          self._trace_data_builder.AddEventsTo(part, trace[field_name])
-
-      if 'metadata' in trace:
-        self._trace_data_builder.SetMetadataFor(
-            trace_data_module.CHROME_TRACE_PART, trace['metadata'])
-
-    elif type(trace) == list:
-      self._trace_data_builder.AddEventsTo(
+    self._trace_data_builder.AddTraceFor(
         trace_data_module.CHROME_TRACE_PART, trace)
-    else:
-      raise TracingUnexpectedResponseException('Unexpected trace type')
     self._has_received_all_tracing_data = True
 
   def Close(self):
     self._inspector_websocket.UnregisterDomain(self._TRACING_DOMAIN)
     self._inspector_websocket = None
 
   @decorators.Cache
   def IsTracingSupported(self):
     req = {'method': 'Tracing.hasCompleted'}
     res = self._inspector_websocket.SyncRequest(req, timeout=10)
     return not res.get('response')