Prompt for extension install on startup even when --force-app-mode is passed

This ensures that extensions installed with --install-from-webstore still show
an install prompt.

BUG=342949
TEST=See bug for repro
NOTRY=true

Review URL: https://codereview.chromium.org/146093006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250900 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/extensions/startup_helper.cc

@@ -293,9 +293,8 @@ bool StartupHelper::InstallFromWebstore(const CommandLine& cmd_line,
   }
 
   AppInstallHelper helper;
-  helper.BeginInstall(profile, id,
-                      !cmd_line.HasSwitch(switches::kForceAppMode),
-                      base::MessageLoop::QuitWhenIdleClosure());
+  helper.BeginInstall(
+      profile, id, true, base::MessageLoop::QuitWhenIdleClosure());
 
   base::MessageLoop::current()->Run();
   if (!helper.success())