Use CategoryFilter::kDefaultCategoryFilterString instead of "*" as the default category

build/android/adb_profile_chrome.py

 #!/usr/bin/env python
 #
 # 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 gzip
 import logging
 import optparse
 import os
@@ skipping 16 matching lines @@
   }
   supported_browsers.update(constants.PACKAGE_INFO)
   unsupported_browsers = ['content_browsertests', 'gtest', 'legacy_browser']
   for browser in unsupported_browsers:
     del supported_browsers[browser]
   return supported_browsers
 
 
 def _StartTracing(adb, package_info, categories, continuous):
   adb.BroadcastIntent(package_info.package, 'GPU_PROFILER_START',
-                      '-e categories "%s"' % categories,
+                      '-e categories "%s"' % categories if categories else '',
                       '-e continuous' if continuous else '')
 
 
 def _StopTracing(adb, package_info):
   adb.BroadcastIntent(package_info.package, 'GPU_PROFILER_STOP')
 
 
 def _GetLatestTraceFileName(adb, check_for_multiple_traces=True):
   # Chrome logs two different messages related to tracing:
   #
@@ skipping 76 matching lines @@
   _StopTracing(adb, package_info)
   _PrintMessage('done')
 
   # Wait a bit for the browser to finish writing the trace file.
   time.sleep(interval / 4 + 1)
 
   _DownloadLatestTrace(adb, compress, check_for_multiple_traces=False)
 
 
 def _ComputeCategories(options):
-  categories = [options.categories]
+  categories = [options.categories] if options.categories else []
   if options.trace_cc:
     categories.append('disabled-by-default-cc.debug*')
   if options.trace_gpu:
     categories.append('disabled-by-default-gpu.debug*')
   return ",".join(categories)
 
 
 def main():
   parser = optparse.OptionParser(description='Record about://tracing profiles '
                                  'from Android browsers. See http://dev.'
@@ skipping 11 matching lines @@
 
   auto_options = optparse.OptionGroup(parser, 'Automated tracing')
   auto_options.add_option('-t', '--time', help='Profile for N seconds and '
                           'download the resulting trace.', metavar='N',
                           type='float')
   parser.add_option_group(auto_options)
 
   categories = optparse.OptionGroup(parser, 'Trace categories')
   categories.add_option('-c', '--categories', help='Select categories to trace '
                         'with comma-delimited wildcards, e.g., '
-                        '"*", "cat1*,-cat1a". Default is "*".', default='*')
+                        '"*", "cat1*,-cat1a".')

[Sami, 2013/10/14 11:22:19]

Having an emptry string imply default categories is a little problematic since
there's then no way to specify that you want no categories at all. Doing that
will be more useful after https://codereview.chromium.org/25686006/ when you
might only want to trace systrace categories.

How about we add a new constant, say, _DEFAULT_CHROME_CATEGORIES, that this
option will be set to by default. The _StartTracing then knows to avoid
specifying any categories in the intent if that constant is passed in.

[Xianzhu, 2013/10/14 16:44:40]

Do you mean '--categories ""' to opt-out chromium tracing? This seems
inconsistent with CategoryFilter which treats empty filter string as the default
categories. How about telling user here to pass "-*" for "no categories" (in
your patch)?

   categories.add_option('--trace-cc', help='Enable extra trace categories for '
                         'compositor frame viewer data.', action='store_true')
   categories.add_option('--trace-gpu', help='Enable extra trace categories for '
                         'GPU data.', action='store_true')
   parser.add_option_group(categories)
 
   parser.add_option('-o', '--output', help='Save profile output to file. '
                     'Default is "/sdcard/Download/chrome-profile-results-*".')
   parser.add_option('--continuous', help='Using the trace buffer as a ring '
                     'buffer, continuously profile until stopped.',
@@ skipping 26 matching lines @@
     _StopTracing(adb, package_info)
   elif options.download:
     _DownloadLatestTrace(adb, options.compress)
   elif options.time:
     _CaptureAndDownloadTimedTrace(adb, package_info, categories, options.time,
                                   options.continuous, options.compress)
 
 
 if __name__ == '__main__':
   sys.exit(main())