Port perf.py's _LoginToGoogleAccount to chrome_remote_control

tools/chrome_remote_control/chrome_remote_control/tab_credentials.py

Index: tools/chrome_remote_control/chrome_remote_control/tab_credentials.py
diff --git a/tools/chrome_remote_control/chrome_remote_control/tab_credentials.py b/tools/chrome_remote_control/chrome_remote_control/tab_credentials.py
new file mode 100644
index 0000000000000000000000000000000000000000..a90371c8370c48413da36eeb40b82e615bb85af4
--- /dev/null
+++ b/tools/chrome_remote_control/chrome_remote_control/tab_credentials.py
@@ -0,0 +1,22 @@
+# Copyright (c) 2012 The Chromium Authors. All rights reserved.

[dtu, 2012/09/24 21:35:10]

I kind of think this class is unnecessary and the credentials_backend should be
owned by the PageRunner, not the tab.

[dtu, 2012/09/24 21:50:01]

Saw nduca's comment. His way works better, so the browser can keep track of the
credentials state.

+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import google_credentials_backend
+
+class TabCredentials(object):
+  def __init__(self, tab):
+    self._tab = tab
+    self._credentials_backends = \
+        [google_credentials_backend.GoogleCredentialsBackend(self._tab)]
+
+  def _GetCredentialsBackend(self, credentials_type):
+    for backend in self._credentials_backends:
+      if credentials_type == backend.label:
+        return backend
+
+  def LoginNeeded(self, credentials_type):

[tonyg, 2012/09/24 20:41:01]

Wonder if LoginNeeded/LoginNoLongerNeeded should be __enter__/__exit__

+    self._GetCredentialsBackend(credentials_type).LoginNeeded()
+
+  def LoginNoLongerNeeded(self, credentials_type):
+    self._GetCredentialsBackend(credentials_type).LoginNoLongerNeeded()