[Cleanup] List trace categories through script as shown by trace record dialog

tools/profile_chrome/chrome_controller.py

 # Copyright 2014 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 os
 import re
 import time
 
 from profile_chrome import controllers
@@ skipping 33 matching lines @@
       json_category_list = device.old_interface.WaitForLogMatch(
           re.compile(r'{"traceCategoriesList(.*)'), None, timeout=5).group(0)
     except pexpect.TIMEOUT:
       raise RuntimeError('Performance trace category list marker not found. '
                          'Is the correct version of the browser running?')
 
     record_categories = []
     disabled_by_default_categories = []
     json_data = json.loads(json_category_list)['traceCategoriesList']
     for item in json_data:
-      if item.startswith('disabled-by-default'):
-        disabled_by_default_categories.append(item)
-      else:
-        record_categories.append(item)
+      categories = item.split(',')
+      try:
+        if item.startswith('disabled-by-default'):

[dsinclair, 2014/11/07 00:05:25]

Don't we want to do this check against each item in categories? If the second
category is disabled by default we'd put it in the wrong list?

It seems like like we want to add a loop over categories and do the original if
statement on each of the items in that list?

[r.kasibhatla, 2014/11/07 09:58:47]

Correct. I was trying to club too many conditions in single statement. I have
corrected it now. :)

+          disabled_by_default_categories.append(
+              next(category for category in categories
+                  if category not in disabled_by_default_categories))
+        else:
+          record_categories.append(
+              next(category for category in categories
+                  if category not in record_categories))
+      except StopIteration, e:
+        pass
 
     return record_categories, disabled_by_default_categories
 
   def StartTracing(self, interval):
     self._trace_interval = interval
     self._device.old_interface.SyncLogCat()
     start_extras = {'categories': ','.join(self._categories)}
     if self._ring_buffer:
       start_extras['continuous'] = None
     self._device.BroadcastIntent(intent.Intent(
@@ skipping 30 matching lines @@
       self._device.SetProp(_HEAP_PROFILE_MMAP_PROPERTY, 0)
 
   def PullTrace(self):
     # Wait a bit for the browser to finish writing the trace file.
     time.sleep(self._trace_interval / 4 + 1)
 
     trace_file = self._trace_file.replace('/storage/emulated/0/', '/sdcard/')
     host_file = os.path.join(os.path.curdir, os.path.basename(trace_file))
     self._device.PullFile(trace_file, host_file)
     return host_file