Add ShellAcceleratorController that manages global keyboard accelerators (2nd try).

ui/aura_shell/shell.h

Index: ui/aura_shell/shell.h
diff --git a/ui/aura_shell/shell.h b/ui/aura_shell/shell.h
index 0ab72bc8e84f9d021eb1510a7b75ea850348f09a..228c00f430d1a5510aa0af9f5edc1be4927997a5 100644
--- a/ui/aura_shell/shell.h
+++ b/ui/aura_shell/shell.h
@@ -27,6 +27,7 @@ class Rect;
 namespace aura_shell {
 
 class Launcher;
+class ShellAcceleratorController;
 class ShellDelegate;
 
 namespace internal {
@@ -34,6 +35,7 @@ class AppList;
 class DragDropController;
 class ShadowController;
 class ShelfLayoutController;
+class ShellAcceleratorFilter;
 class WorkspaceController;
 }
 
@@ -66,6 +68,10 @@ class AURA_SHELL_EXPORT Shell {
   // Toggles app list.
   void ToggleAppList();
 
+  ShellAcceleratorController* accelerator_controller() {
+    return accelerator_controller_.get();
+  }
+
   ShellDelegate* delegate() { return delegate_.get(); }
   Launcher* launcher() { return launcher_.get(); }
 
@@ -91,6 +97,8 @@ class AURA_SHELL_EXPORT Shell {
 
   base::WeakPtrFactory<Shell> method_factory_;
 
+  scoped_ptr<ShellAcceleratorController> accelerator_controller_;
+
   scoped_ptr<ShellDelegate> delegate_;
 
   scoped_ptr<Launcher> launcher_;
@@ -102,6 +110,9 @@ class AURA_SHELL_EXPORT Shell {
   scoped_ptr<internal::ShelfLayoutController> shelf_layout_controller_;
   scoped_ptr<internal::ShadowController> shadow_controller_;
 
+  // An event filter that pre-handles global accelerators.
+  scoped_ptr<internal::ShellAcceleratorFilter> accelerator_filter_;
+
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };