Make accelerators not to work when the keyboard overlay is shown.

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index 13614653b4e875fb38fb8aeeb73aa800c9640cd5..fb03adfff7e3cb1c37f58a2abd01b0c7be8022a2 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -84,8 +84,8 @@ class FocusCycler;
 class MagnificationController;
 class DisplayController;
 class MouseCursorEventFilter;
+class OverlayEventFilter;
 class PanelLayoutManager;
-class PartialScreenshotEventFilter;
 class ResizeShadowController;
 class RootWindowController;
 class RootWindowLayoutManager;
@@ -261,8 +261,8 @@ class ASH_EXPORT Shell : aura::CursorDelegate {
   internal::EventRewriterEventFilter* event_rewriter_filter() {
     return event_rewriter_filter_.get();
   }
-  internal::PartialScreenshotEventFilter* partial_screenshot_filter() {
-    return partial_screenshot_filter_.get();
+  internal::OverlayEventFilter* overlay_filter() {
+    return overlay_filter_.get();
   }
   DesktopBackgroundController* desktop_background_controller() {
     return desktop_background_controller_.get();
@@ -445,7 +445,7 @@ class ASH_EXPORT Shell : aura::CursorDelegate {
 
   // An event filter that pre-handles key events while the partial
   // screenshot UI is active.
-  scoped_ptr<internal::PartialScreenshotEventFilter> partial_screenshot_filter_;
+  scoped_ptr<internal::OverlayEventFilter> overlay_filter_;
 
   // An event filter which handles system level gestures
   scoped_ptr<internal::SystemGestureEventFilter> system_gesture_filter_;