mus: Introduce AcceleratorRegistrar and AcceleratorHandler.

mash/wm/window_manager_application.cc

Index: mash/wm/window_manager_application.cc
diff --git a/mash/wm/window_manager_application.cc b/mash/wm/window_manager_application.cc
index bc8526802b0b6046fdff575e6337ec4ba73cf11c..c2479aff962e53d96f39e86183e032ddea0989c8 100644
--- a/mash/wm/window_manager_application.cc
+++ b/mash/wm/window_manager_application.cc
@@ -4,11 +4,13 @@
 
 #include "mash/wm/window_manager_application.h"
 
+#include "base/bind.h"
 #include "components/mus/common/util.h"
 #include "components/mus/public/cpp/event_matcher.h"
 #include "components/mus/public/cpp/window.h"
 #include "components/mus/public/cpp/window_tree_connection.h"
 #include "components/mus/public/cpp/window_tree_host_factory.h"
+#include "mash/wm/accelerator_registrar_impl.h"
 #include "mash/wm/background_layout.h"
 #include "mash/wm/shelf_layout.h"
 #include "mash/wm/window_layout.h"
@@ -51,6 +53,11 @@ void WindowManagerApplication::AddAccelerators() {
                             mus::mojom::EVENT_FLAGS_CONTROL_DOWN));
 }
 
+void WindowManagerApplication::OnAcceleratorRegistrarDestroyed(
+    AcceleratorRegistrarImpl* registrar) {
+  accelerator_registrars_.erase(registrar);
+}
+
 void WindowManagerApplication::Initialize(mojo::ApplicationImpl* app) {
   app_ = app;
   tracing_.Initialize(app);
@@ -68,7 +75,8 @@ void WindowManagerApplication::Initialize(mojo::ApplicationImpl* app) {
 
 bool WindowManagerApplication::ConfigureIncomingConnection(
     mojo::ApplicationConnection* connection) {
-  connection->AddService(this);
+  connection->AddService<mus::mojom::AcceleratorRegistrar>(this);
+  connection->AddService<mus::mojom::WindowManager>(this);
   return true;
 }
 
@@ -79,7 +87,12 @@ void WindowManagerApplication::OnAccelerator(uint32_t id,
       window_tree_host_->ActivateNextWindow();
       break;
     default:
-      NOTREACHED() << "Unknown accelerator command: " << id;
+      for (auto* registrar : accelerator_registrars_) {
+        if (registrar->OwnsAccelerator(id)) {
+          registrar->ProcessAccelerator(id, event.Pass());
+          break;
+        }
+      }
   }
 }
 
@@ -115,6 +128,16 @@ void WindowManagerApplication::OnConnectionLost(
 
 void WindowManagerApplication::Create(
     mojo::ApplicationConnection* connection,
+    mojo::InterfaceRequest<mus::mojom::AcceleratorRegistrar> request) {
+  static int accelerator_registrar_count = 0;
+  accelerator_registrars_.insert(new AcceleratorRegistrarImpl(
+      window_tree_host_.get(), ++accelerator_registrar_count, request.Pass(),
+      base::Bind(&WindowManagerApplication::OnAcceleratorRegistrarDestroyed,
+                 base::Unretained(this))));
+}
+
+void WindowManagerApplication::Create(
+    mojo::ApplicationConnection* connection,
     mojo::InterfaceRequest<mus::mojom::WindowManager> request) {
   if (root_) {
     window_manager_binding_.AddBinding(window_manager_.get(), request.Pass());