Loading the Launcher with a Locked Profile launched UserManager.

chrome/browser/ui/app_list/app_list_service_impl.cc

Index: chrome/browser/ui/app_list/app_list_service_impl.cc
diff --git a/chrome/browser/ui/app_list/app_list_service_impl.cc b/chrome/browser/ui/app_list/app_list_service_impl.cc
index 8b5c91422bc3020ad6c4d5bd64f7bb065c7ddcbf..81014606ed85b668536f32e549877f01988554c9 100644
--- a/chrome/browser/ui/app_list/app_list_service_impl.cc
+++ b/chrome/browser/ui/app_list/app_list_service_impl.cc
@@ -18,6 +18,7 @@
 #include "chrome/browser/ui/app_list/app_list_view_delegate.h"
 #include "chrome/browser/ui/app_list/profile_loader.h"
 #include "chrome/browser/ui/app_list/profile_store.h"
+#include "chrome/browser/ui/user_manager.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
@@ -123,6 +124,8 @@ class ProfileStoreImpl : public ProfileStore {
   }
 
   Profile* GetProfileByPath(const base::FilePath& path) override {
+    if (IsProfileLocked(path))

[tapted, 2015/01/21 22:47:20]

nit: I'm pretty sure this can this be DCHECK(!IsProfileLocked(path)).

[Mike Lerman, 2015/01/23 16:58:33]

Oop, thanks! I had meant to remove this completely, but a DCHECK makes sense too
:)

+      return nullptr;
     return profile_manager_->GetProfileByPath(path);
   }
 
@@ -138,6 +141,14 @@ class ProfileStoreImpl : public ProfileStore {
         profile_info.ProfileIsSupervisedAtIndex(profile_index);
   }
 
+  bool IsProfileLocked(const base::FilePath& profile_path) override {
+    ProfileInfoCache& profile_info =
+        g_browser_process->profile_manager()->GetProfileInfoCache();
+    size_t profile_index = profile_info.GetIndexOfProfileWithPath(profile_path);
+    return profile_index != std::string::npos &&
+        profile_info.ProfileIsSigninRequiredAtIndex(profile_index);
+  }
+
  private:
   ProfileManager* profile_manager_;
   base::WeakPtrFactory<ProfileStoreImpl> weak_factory_;