Enable commands API for platform apps.

chrome/browser/ui/gtk/extensions/shell_window_gtk.cc

Index: chrome/browser/ui/gtk/extensions/shell_window_gtk.cc
diff --git a/chrome/browser/ui/gtk/extensions/shell_window_gtk.cc b/chrome/browser/ui/gtk/extensions/shell_window_gtk.cc
index 838353e0c5a122d14904e573ee562ad6d49d0727..6a1193335a653ab50f4e21782cfb967904cd27d5 100644
--- a/chrome/browser/ui/gtk/extensions/shell_window_gtk.cc
+++ b/chrome/browser/ui/gtk/extensions/shell_window_gtk.cc
@@ -6,6 +6,7 @@
 
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/ui/gtk/extensions/extension_keybinding_registry_gtk.h"
 #include "chrome/browser/ui/gtk/gtk_util.h"
 #include "chrome/browser/ui/gtk/gtk_window_util.h"
 #include "chrome/browser/web_applications/web_app.h"
@@ -112,6 +113,11 @@ ShellWindowGtk::ShellWindowGtk(ShellWindow* shell_window,
                      G_CALLBACK(OnButtonPressThunk), this);
   }
 
+  // Add the keybinding registry.
+  extension_keybinding_registry_.reset(
+      new ExtensionKeybindingRegistryGtk(shell_window_->profile(), window_,
+          extensions::ExtensionKeybindingRegistry::PLATFORM_APPS_ONLY));
+
   ui::ActiveWindowWatcherX::AddObserver(this);
 }