Add CommandLineArgumentParameter and use it for WebView tests

build/android/pylib/flag_changer.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.
 
 import logging
 
 from devil.android import device_errors
 
 
 class FlagChanger(object):
@@ skipping 38 matching lines @@
     self._UpdateCommandLineFile()
 
   def AddFlags(self, flags):
     """Appends flags to the command line if they aren't already there.
        Saves the current flags state on the stack, so a call to Restore will
        change the state back to the one preceeding the call to AddFlags.
 
     Args:
       flags: A sequence of flags to add on, eg. ['--single-process'].
     """
-    new_flags = self._state_stack[-1].copy()
-    new_flags.update(flags)
-    self.ReplaceFlags(new_flags)
+    self.PushFlags(add=flags)
 
   def RemoveFlags(self, flags):
     """Removes flags from the command line, if they exist.
        Saves the current flags state on the stack, so a call to Restore will
        change the state back to the one preceeding the call to RemoveFlags.
 
        Note that calling RemoveFlags after AddFlags will result in having
        two nested states.
 
     Args:
       flags: A sequence of flags to remove, eg. ['--single-process'].  Note
              that we expect a complete match when removing flags; if you want
              to remove a switch with a value, you must use the exact string
              used to add it in the first place.
     """
+    self.PushFlags(remove=flags)
+
+  def PushFlags(self, add=None, remove=None):
+    """Appends and removes flags to/from the command line if they aren't already
+       there. Saves the current flags state on the stack, so a call to Restore
+       will change the state back to the one preceeding the call to PushFlags.
+
+    Args:
+      add: A list of flags to add on, eg. ['--single-process'].
+      remove: A list of flags to remove, eg. ['--single-process'].  Note that we
+              expect a complete match when removing flags; if you want to remove
+              a switch with a value, you must use the exact string used to add
+              it in the first place.
+    """
     new_flags = self._state_stack[-1].copy()
-    new_flags.difference_update(flags)
+    if add:
+      new_flags.update(add)
+    if remove:
+      new_flags.difference_update(remove)
     self.ReplaceFlags(new_flags)
 
   def Restore(self):
     """Restores the flags to their state prior to the last AddFlags or
        RemoveFlags call.
     """
     # The initial state must always remain on the stack.
     assert len(self._state_stack) > 1, (
       "Mismatch between calls to Add/RemoveFlags and Restore")
     self._state_stack.pop()
@@ skipping 62 matching lines @@
 
     # Tack on the last flag.
     if not current_flag:
       if within_quotations:
         logging.warn('Unterminated quoted argument: ' + line)
     else:
       tokenized_flags.append(current_flag)
 
     # Return everything but the program name.
     return tokenized_flags[1:]