Make sure the app section opens whenever a new apps is

chrome/browser/dom_ui/shown_sections_handler.h

Index: chrome/browser/dom_ui/shown_sections_handler.h
diff --git a/chrome/browser/dom_ui/shown_sections_handler.h b/chrome/browser/dom_ui/shown_sections_handler.h
index be077354a34ee5a09cfb62b597338710c8729a8d..e82c3fb7a105dd656f0178d9d8ef3b0dec635bce 100644
--- a/chrome/browser/dom_ui/shown_sections_handler.h
+++ b/chrome/browser/dom_ui/shown_sections_handler.h
@@ -8,6 +8,7 @@
 
 #include "chrome/browser/dom_ui/dom_ui.h"
 #include "chrome/common/notification_observer.h"
+#include "chrome/common/notification_registrar.h"
 #include "chrome/browser/prefs/pref_change_registrar.h"
 
 class DOMUI;
@@ -23,6 +24,9 @@ enum Section {
   THUMB = 1 << 0,
   APPS = 1 << 6,
 
+  // We use the low 16 bits for sections, the high 16 bits for minimized state.
+  ALL_SECTIONS_MASK = 0x0000FFFF,
+
   // If one of these is set, then the corresponding section is shown minimized
   // at the bottom of the NTP and no data is directly visible on the NTP.
   MINIMIZED_THUMB = 1 << (0 + 16),
@@ -61,7 +65,8 @@ class ShownSectionsHandler : public DOMMessageHandler,
 
  private:
   PrefService* pref_service_;
-  PrefChangeRegistrar registrar_;
+  PrefChangeRegistrar pref_registrar_;
+  NotificationRegistrar notification_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(ShownSectionsHandler);
 };