cc: Change scoped_ptr<T>() to nullptr.

cc/PRESUBMIT.py

 # Copyright (c) 2012 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.
 
 """Top-level presubmit script for cc.
 
 See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
 for more details about the presubmit API built into depot_tools.
 """
 
@@ skipping 152 matching lines @@
       # return scoped_ptr<T>(foo);
       # bar = scoped_ptr<T>(foo);
       # But allow:
       # return scoped_ptr<T[]>(foo);
       # bar = scoped_ptr<T[]>(foo);
       if re.search(r'(=|\breturn)\s*scoped_ptr<.*?(?<!])>\([^)]+\)', line):
         errors.append(output_api.PresubmitError(
           ('%s:%d uses explicit scoped_ptr constructor. ' +
            'Use make_scoped_ptr() instead.') % (f.LocalPath(), line_number)))
       # Disallow:
-      # return scoped_ptr<T>();
-      # bar = scoped_ptr<T>();
-      if re.search(r'(=|\breturn)\s*scoped_ptr<.*?>\(\)', line):
+      # scoped_ptr<T>()
+      if re.search(r'\bscoped_ptr<.*?>\(\)', line):
         errors.append(output_api.PresubmitError(
           '%s:%d uses scoped_ptr<T>(). Use nullptr instead.' %
           (f.LocalPath(), line_number)))
       # Disallow:
       # foo.PassAs<T>();
       if re.search(r'\bPassAs<.*?>\(\)', line):
         errors.append(output_api.PresubmitError(
           '%s:%d uses PassAs<T>(). Use Pass() instead.' %
           (f.LocalPath(), line_number)))
   return errors
@@ skipping 186 matching lines @@
   return {
     'tryserver.blink': {
       'linux_blink_rel': set(['defaulttests']),
     },
     'tryserver.chromium.gpu': {
       'linux_gpu': set(['defaulttests']),
       'mac_gpu': set(['defaulttests']),
       'win_gpu': set(['defaulttests']),
     },
   }