Implement "pinned" mode in ash.

ash/accelerators/accelerator_controller.cc

Index: ash/accelerators/accelerator_controller.cc
diff --git a/ash/accelerators/accelerator_controller.cc b/ash/accelerators/accelerator_controller.cc
index d9dbbf696eb1bdc892df6d3387876212a2d9a5f9..6407577ae1efc6e085c3a066bc9dcd10caa3fcfd 100644
--- a/ash/accelerators/accelerator_controller.cc
+++ b/ash/accelerators/accelerator_controller.cc
@@ -1402,6 +1402,10 @@ bool AcceleratorController::ShouldActionConsumeKeyEvent(
 
 AcceleratorController::AcceleratorProcessingRestriction
 AcceleratorController::GetAcceleratorProcessingRestriction(int action) {
+  if (WmShell::Get()->IsPinned() &&
+      reserved_actions_.find(action) == reserved_actions_.end()) {
+    return RESTRICTION_PREVENT_PROCESSING_AND_PROPAGATION;
+  }

[oshima, 2016/06/17 10:26:53]

won't this also prevent power/audio accelerators?

[hidehiko, 2016/06/17 17:19:21]

Good point. I added the table, based on the reference device's behavior. It
should be somehow reasonable, but maybe we want to update it in a follow up CL.

   ash::Shell* shell = ash::Shell::GetInstance();
   if (!shell->session_state_delegate()->IsActiveUserSessionStarted() &&
       actions_allowed_at_login_screen_.find(action) ==