Support global keyboard commands on Chrome OS.

ash/accelerators/accelerator_controller.h

Index: ash/accelerators/accelerator_controller.h
diff --git a/ash/accelerators/accelerator_controller.h b/ash/accelerators/accelerator_controller.h
index 374286e50dd15b9c637cbfd84d5fe8d832aceddf..bc36bf9261dec348d726fe2eb731a625a4a01c23 100644
--- a/ash/accelerators/accelerator_controller.h
+++ b/ash/accelerators/accelerator_controller.h
@@ -38,6 +38,21 @@ class ASH_EXPORT AcceleratorController : public ui::AcceleratorTarget {
   AcceleratorController();
   virtual ~AcceleratorController();
 
+  // A list of possible ways in which an accelerator should be restricted before
+  // processing. Any target registered with this controller should respect
+  // restrictions by calling |GetAcceleratorProcessingRestriction| during
+  // processing.
+  enum AcceleratorProcessingRestriction {
+    // Process the accelerator normally.
+    RESTRICTION_NONE,
+
+    // Don't process the accelerator.
+    RESTRICTION_PREVENT_PROCESSING,
+
+    // Don't process the accelerator and prevent propagation to other targets.
+    RESTRICTION_PREVENT_PROCESSING_AND_PROPAGATION
+  };
+
   // Registers a global keyboard accelerator for the specified target. If
   // multiple targets are registered for an accelerator, a target registered
   // later has higher priority.
@@ -71,6 +86,11 @@ class ASH_EXPORT AcceleratorController : public ui::AcceleratorTarget {
   bool PerformAction(int action,
                      const ui::Accelerator& accelerator);
 
+  // Returns which restriction applies for the given accelerator and action.
+  AcceleratorProcessingRestriction GetAcceleratorProcessingRestriction(
+      int action,
+      const ui::Accelerator& accelerator);
+
   // Overridden from ui::AcceleratorTarget:
   virtual bool AcceleratorPressed(const ui::Accelerator& accelerator) OVERRIDE;
   virtual bool CanHandleAccelerators() const OVERRIDE;