Revert of Restrict use of two app-launching command line flags

chrome/browser/extensions/unpacked_installer.cc

Index: chrome/browser/extensions/unpacked_installer.cc
diff --git a/chrome/browser/extensions/unpacked_installer.cc b/chrome/browser/extensions/unpacked_installer.cc
index 988293d951b887b6b6b1308bd7aaec09155e0c6f..f812a2f5f368e2391f6404ffb8128699c844337f 100644
--- a/chrome/browser/extensions/unpacked_installer.cc
+++ b/chrome/browser/extensions/unpacked_installer.cc
@@ -40,10 +40,6 @@
 const char kUnpackedExtensionsBlacklistedError[] =
     "Loading of unpacked extensions is disabled by the administrator.";
 
-const char kUnpackedExtensionInsteadOfAppError[] =
-    "App loading flags cannot be used to load extensions. Please use "
-    "--load-extension instead.";
-
 const char kImportMinVersionNewer[] =
     "'import' version requested is newer than what is installed.";
 const char kImportMissing[] = "'import' extension is not installed.";
@@ -134,8 +130,7 @@
 }
 
 bool UnpackedInstaller::LoadFromCommandLine(const base::FilePath& path_in,
-                                            std::string* extension_id,
-                                            bool only_allow_apps) {
+                                            std::string* extension_id) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK(extension_path_.empty());
 
@@ -156,16 +151,6 @@
   install_checker_.set_extension(
       file_util::LoadExtension(
           extension_path_, Manifest::COMMAND_LINE, GetFlags(), &error).get());
-
-  if (only_allow_apps && !extension()->is_platform_app()) {
-#if defined(GOOGLE_CHROME_BUILD)
-    // Avoid crashing for users with hijacked shortcuts.
-    return true;
-#else
-    ReportExtensionLoadError(kUnpackedExtensionInsteadOfAppError);
-    return false;
-#endif
-  }
 
   if (!extension() ||
       !extension_l10n_util::ValidateExtensionLocales(