Add support for managing active state of platform apps

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index b7f7443b5376b7398d8961bcfda81d346fea3325..0b3a92cdc61c09be794c5def4698a6a885fcb12c 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -649,11 +649,6 @@ Shell::~Shell() {
   aura::client::SetVisibilityClient(root_window, NULL);
   visibility_controller_.reset();
 
-  // Delete the activation controller after other controllers
-  // because they might have registered ActivationChangeObserver.
-  aura::client::SetActivationClient(root_window, NULL);
-  activation_controller_.reset();
-
   // Launcher widget has a InputMethodBridge that references to
   // input_method_filter_'s input_method_. So explicitly release launcher_
   // before input_method_filter_. And this needs to be after we delete all
@@ -661,6 +656,11 @@ Shell::~Shell() {
   // LauncherModel during close.
   launcher_.reset();
 
+  // Delete the activation controller after other controllers and launcher
+  // because they might have registered ActivationChangeObserver.
+  aura::client::SetActivationClient(root_window, NULL);
+  activation_controller_.reset();
+
   DCHECK(instance_ == this);
   instance_ = NULL;