Chrome OS multi-profiles backend and UI.
* Tray - launch login UI for multi-profiles
* UserManager: GetLoggedInUsers(), SwitchActiveUser(),
  add GetActiveUser() which will later replace GetLoggedInUser()
* Login UI: support "sign in to add" mode

Notifications:
* Pass chromeos::User* in details for
  - NOTIFICATION_LOGIN_USER_CHANGED
  - NOTIFICATION_ACTIVE_USER_CHANGED
  - NOTIFICATION_SESSION_STARTED
* Add NOTIFICATION_ACTIVE_USER_CHANGED (only when switching users for now)

Multi-profile hacks
* Initialize BrowserPolicyConnector only for primary user (http://crbug.com/230349)
* Redirect logging only once (http://crbug.com/230345)
* OAuth2LoginManager tracks only last logged in user (http://crbug.com/230342)

Depends on:
* Changes in ProfileManager https://codereview.chromium.org/14028010/
* Adding concept of "signin profile" https://codereview.chromium.org/13633003/

BUG=180903,217016
TEST=ProfileManager tests, manual (with all CLs applied and --multi-profiles)

Review URL: https://codereview.chromium.org/14139003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@194185 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/common/logging_chrome.cc b/chrome/common/logging_chrome.cc
index 9095873..8a5dd4b2 100644
--- a/chrome/common/logging_chrome.cc
+++ b/chrome/common/logging_chrome.cc
@@ -216,6 +216,13 @@
 }
 
 void RedirectChromeLogging(const CommandLine& command_line) {
+  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kMultiProfiles) &&
+      chrome_logging_redirected_) {
+    // TODO(nkostylev): Support multiple active users. http://crbug.com/230345
+    LOG(ERROR) << "NOT redirecting logging for multi-profiles case.";
+    return;
+  }
+
   DCHECK(!chrome_logging_redirected_) <<
     "Attempted to redirect logging when it was already initialized.";