Add enable-app-launcher-shim to chrome://flags.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/about_flags.h"
 
 #include <algorithm>
 #include <iterator>
 #include <map>
 #include <set>
@@ skipping 1445 matching lines @@
     kOsAndroid,
     SINGLE_VALUE_TYPE(switches::kEnableDraggableMenuButton)
   },
   {
     "enable-reset-profile-settings",
     IDS_FLAGS_ENABLE_RESET_PROFILE_SETTINGS_NAME,
     IDS_FLAGS_ENABLE_RESET_PROFILE_SETTINGS_DESCRIPTION,
     kOsAll,
     SINGLE_VALUE_TYPE(switches::kEnableResetProfileSettings)
   },
+#if defined(OS_MACOSX)
+  {
+    "enable-app-list-shim",
+    IDS_FLAGS_ENABLE_APP_LIST_SHIM_NAME,
+    IDS_FLAGS_ENABLE_APP_LIST_SHIM_DESCRIPTION,
+    kOsMac,
+    ENABLE_DISABLE_VALUE_TYPE_AND_VALUE(
+        switches::kEnableAppListShim, "1",

[benwells, 2013/05/29 06:33:38]

I don't remember the windows one being so complicated. Why not imply disable
from lack of the switch?

[tapted, 2013/05/29 06:37:24]

The rationale for doing it this way is that it avoids a by-default post-task to
the file thread to ensure that it doesn't exist, on everyone's Chrome startup.

But, if we don't care about that, I'm happy to change it :D

+        switches::kEnableAppListShim, "0")
+  },
+#endif
 };
 
 const Experiment* experiments = kExperiments;
 size_t num_experiments = arraysize(kExperiments);
 
 // Stores and encapsulates the little state that about:flags has.
 class FlagsState {
  public:
   FlagsState() : needs_restart_(false) {}
   void ConvertFlagsToSwitches(PrefService* prefs, CommandLine* command_line);
@@ skipping 484 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags