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

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index b06be7348cdfcacdbec32746b3f23bf9e32b9b77..d803450125ed8018f1dacb2991edef4225c7c46f 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -1463,6 +1463,17 @@ const Experiment kExperiments[] = {
     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;