[android] Update FlagChanger to work with additional apks.

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 constants
 import logging
 import traceback
-import warnings
 
 
-# Location where chrome reads command line flags from
-CHROME_COMMAND_FILE = '/data/local/chrome-command-line'
-
 class FlagChanger(object):
   """Changes the flags Chrome runs with.
 
   There are two different use cases for this file:
   * Flags are permanently set by calling Set().
   * Flags can be temporarily set for a particular set of unit tests.  These
     tests should call Restore() to revert the flags to their original state
     once the tests have completed.
   """
 
-  def __init__(self, android_cmd):
-    self._android_cmd = android_cmd
+  def __init__(self, adb,
+               cmdline_file=constants.PACKAGE_INFO['chrome'].cmdline_file):
+    """Initializes the FlagChanger and records the original arguments.
+
+    Args:
+      adb: An instance of AndroidCommands.
+      cmdline_file: Path to the command line file on the device.
+    """
+    self._adb = adb
+    self._cmdline_file = cmdline_file
 
     # Save the original flags.
-    self._orig_line = self._android_cmd.GetFileContents(CHROME_COMMAND_FILE)
+    self._orig_line = self._adb.GetFileContents(self._cmdline_file)
     if self._orig_line:
       self._orig_line = self._orig_line[0].strip()
 
     # Parse out the flags into a list to facilitate adding and removing flags.
     self._current_flags = self._TokenizeFlags(self._orig_line)
 
   def Get(self):
     """Returns list of current flags."""
     return self._current_flags
 
@@ skipping 44 matching lines @@
   def Restore(self):
     """Restores the flags to their original state."""
     self._current_flags = self._TokenizeFlags(self._orig_line)
     self._UpdateCommandLineFile()
 
   def _UpdateCommandLineFile(self):
     """Writes out the command line to the file, or removes it if empty."""
     logging.info('Current flags: %s', self._current_flags)
 
     if self._current_flags:
-      self._android_cmd.SetProtectedFileContents(CHROME_COMMAND_FILE,
-                                        'chrome ' +
-                                        ' '.join(self._current_flags))
+      # The first command line argument doesn't matter as we are not actually
+      # launching the chrome executable using this command line.
+      self._adb.SetProtectedFileContents(self._cmdline_file,
+                                         ' '.join(['_'] + self._current_flags))
     else:
-      self._android_cmd.RunShellCommand('su -c rm ' + CHROME_COMMAND_FILE)
+      self._adb.RunShellCommand('su -c rm ' + self._cmdline_file)
 
   def _TokenizeFlags(self, line):
     """Changes the string containing the command line into a list of flags.
 
     Follows similar logic to CommandLine.java::tokenizeQuotedArguments:
     * Flags are split using whitespace, unless the whitespace is within a
       pair of quotation marks.
     * Unlike the Java version, we keep the quotation marks around switch
       values since we need them to re-create the file when new flags are
       appended.
@@ skipping 22 matching lines @@
       elif not within_quotations and (c is ' ' or c is '\t'):
         if current_flag is not "":
           tokenized_flags.append(current_flag)
           current_flag = ""
       else:
         current_flag += c
 
     # Tack on the last flag.
     if not current_flag:
       if within_quotations:
-        warnings.warn("Unterminated quoted string: " + current_flag)
+        logging.warn('Unterminated quoted argument: ' + line)
     else:
       tokenized_flags.append(current_flag)
 
     # Return everything but the program name.
     return tokenized_flags[1:]