[cros] Fake a stub user login when no --login-manager and --login-user are given.

chrome/browser/chromeos/chrome_browser_main_chromeos.cc

Index: chrome/browser/chromeos/chrome_browser_main_chromeos.cc
diff --git a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
index 280082a59af8cca2d8a46687e245be68ddb558fa..f84e8a4f447831481d9810c4d377d0cd61114ce9 100644
--- a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
+++ b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
@@ -79,6 +79,13 @@
 #include "net/base/network_change_notifier.h"
 #include "net/url_request/url_request.h"
 
+namespace {
+
+// Username for stub login when not running on ChromeOS.
+const char kStubUsername[] = "stub-user@example.com";
+
+}
+
 class MessageLoopObserver : public MessageLoopForUI::Observer {
   virtual base::EventStatus WillProcessEvent(
       const base::NativeEvent& event) OVERRIDE {
@@ -230,14 +237,34 @@ ChromeBrowserMainPartsChromeos::~ChromeBrowserMainPartsChromeos() {
 // content::BrowserMainParts and ChromeBrowserMainExtraParts overrides ---------
 
 void ChromeBrowserMainPartsChromeos::PreEarlyInitialization() {
+  CommandLine* singleton_command_line = CommandLine::ForCurrentProcess();
+
   if (parsed_command_line().HasSwitch(switches::kGuestSession)) {
     // Disable sync and extensions if we're in "browse without sign-in" mode.
-    CommandLine* singleton_command_line = CommandLine::ForCurrentProcess();
     singleton_command_line->AppendSwitch(switches::kDisableSync);
     singleton_command_line->AppendSwitch(switches::kDisableExtensions);
     browser_defaults::bookmarks_enabled = false;
   }
 
+  // If we're not running on real ChromeOS hardware (or under VM), and are not
+  // showing the login manager or attempting a command line login, login with a
+  // stub user.
+  if (!base::chromeos::IsRunningOnChromeOS() &&
+      !parsed_command_line().HasSwitch(switches::kLoginManager) &&
+      !parsed_command_line().HasSwitch(switches::kLoginUser) &&
+      !parsed_command_line().HasSwitch(switches::kGuestSession)) {
+    singleton_command_line->AppendSwitchASCII(switches::kLoginUser,
+                                              kStubUsername);
+    if (!parsed_command_line().HasSwitch(switches::kLoginProfile)) {
+      // This must be kept in sync with TestingProfile::kTestUserProfileDir.
+      singleton_command_line->AppendSwitchASCII(
+          switches::kLoginProfile, "test-user");
+    }
+    LOG(INFO) << "Running as stub user with profile dir: "
+              << singleton_command_line->GetSwitchValuePath(
+                     switches::kLoginProfile).value();
+  }
+
   ChromeBrowserMainPartsLinux::PreEarlyInitialization();
 }