app_list: Disable Drive app integration for M39.

ui/app_list/app_list_switches.cc

Index: ui/app_list/app_list_switches.cc
diff --git a/ui/app_list/app_list_switches.cc b/ui/app_list/app_list_switches.cc
index ec2ea1cf8a3019c8917e46fd62f577042417367e..f53ee8e4054903fd3378ecee160358ac26c369a8 100644
--- a/ui/app_list/app_list_switches.cc
+++ b/ui/app_list/app_list_switches.cc
@@ -78,8 +78,9 @@ bool IsCenteredAppListEnabled() {
 
 bool IsDriveAppsInAppListEnabled() {
 #if defined(OS_CHROMEOS)
-  return !CommandLine::ForCurrentProcess()->HasSwitch(
-      kDisableDriveAppsInAppList);
+  // Disable Drive app integration due to http://crbug.com/420034

[Albert Bodenhamer, 2014/10/08 23:25:59]

If we do it this way, the option will still show in about:flags, but wont do
anything.  I don't think we want that either.

Can't we just revert the change you landed that enabled it by default?

+  // TODO(xiyuan): Revisit this after the bug is fixed.
+  return false;
 #else
   return false;
 #endif