Upstream: Test scripts for Android (phase 2)

build/android/flag_changer.py

+#!/usr/bin/python
+# Copyright (c) 2011 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.
+
+
+# Location where chrome reads command line flags from
+CHROME_COMMAND_FILE = '/data/local/chrome-command-line'
+
+
+class FlagChanger(object):
+  """Temporarily changes the flags Chrome runs with."""
+
+  def __init__(self, android_cmd):
+    self.android_cmd = android_cmd
+    self.old_flags = None
+
+  def Set(self, flags, append=False):
+    """Sets the command line flags used when chrome is started.
+
+    Args:
+      flags: A list of flags to set, eg. ['--single-process'].
+      append: Whether to append to existing flags or overwrite them.
+    """
+    if flags: assert flags[0] != 'chrome'

[Nirnimesh, 2011/10/21 08:16:15]

move "assert flags[0] != 'chrome'" to next line

[michaelbai, 2011/10/21 21:08:41]

Done.

+
+    if not self.old_flags:
+      self.old_flags = self.android_cmd.GetFileContents(CHROME_COMMAND_FILE)
+      if self.old_flags: self.old_flags = self.old_flags[0].strip()

[Nirnimesh, 2011/10/21 08:16:15]

same here

[michaelbai, 2011/10/21 21:08:41]

Done.

+
+    if append and self.old_flags:
+      # Avoid appending flags that already present.

[Nirnimesh, 2011/10/21 08:16:15]

that -> that are

[michaelbai, 2011/10/21 21:08:41]

Done.

+      new_flags = filter(lambda flag: self.old_flags.find(flag) == -1, flags)
+      self.android_cmd.SetFileContents(CHROME_COMMAND_FILE,
+                                       self.old_flags + ' ' +
+                                       ' '.join(new_flags))
+    else:
+      self.android_cmd.SetFileContents(CHROME_COMMAND_FILE,
+                                       'chrome ' + ' '.join(flags))
+
+  def Restore(self):

[Nirnimesh, 2011/10/21 08:16:15]

I'd recommend calling Restore in the d'tor as well, so that the caller does not
have to.

[michaelbai, 2011/10/21 21:08:41]

I checked all the code using FlagChanger, it seemed that Restore when instance
gone is not the typical use case. I'd not change it to avoid tricks. 

+    """Restores the flags to their original state."""
+    if self.old_flags == None:
+      return  # Set() was never called.
+    elif self.old_flags:
+      self.android_cmd.SetFileContents(CHROME_COMMAND_FILE, self.old_flags)
+    else:
+      self.android_cmd.RunShellCommand('rm ' + CHROME_COMMAND_FILE)