Convert DeviceManagerDelegate to PermissionProvider mojo interface.

device/devices_app/usb/device_manager_impl.h

Index: device/devices_app/usb/device_manager_impl.h
diff --git a/device/devices_app/usb/device_manager_impl.h b/device/devices_app/usb/device_manager_impl.h
index 69b991e99a284afee050132d55565159ac47d6cd..b7d97eccad94e122ebe02d375efc109cb5149d0e 100644
--- a/device/devices_app/usb/device_manager_impl.h
+++ b/device/devices_app/usb/device_manager_impl.h
@@ -14,6 +14,7 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "device/devices_app/usb/public/interfaces/device_manager.mojom.h"
+#include "device/devices_app/usb/public/interfaces/permission_provider.mojom.h"
 #include "third_party/mojo/src/mojo/public/cpp/bindings/array.h"
 #include "third_party/mojo/src/mojo/public/cpp/bindings/interface_request.h"
 #include "third_party/mojo/src/mojo/public/cpp/bindings/strong_binding.h"
@@ -38,7 +39,7 @@ class DeviceManagerImpl : public DeviceManager {
  public:
   DeviceManagerImpl(
       mojo::InterfaceRequest<DeviceManager> request,
-      scoped_ptr<DeviceManagerDelegate> delegate,
+      PermissionProviderPtr permission_provider,
       scoped_refptr<base::SequencedTaskRunner> service_task_runner);
   ~DeviceManagerImpl() override;
 
@@ -58,17 +59,19 @@ class DeviceManagerImpl : public DeviceManager {
   // Callbacks to handle the async responses from the underlying UsbService.
   void OnGetDevices(const GetDevicesCallback& callback,
                     mojo::Array<DeviceInfoPtr> devices);
-  void OnGetInitialDevices(const GetDeviceChangesCallback& callback,
-                           mojo::Array<DeviceInfoPtr> devices);
+  void OnGetInitialDevices(mojo::Array<DeviceInfoPtr> devices);
 
   // Methods called by |helper_| when devices are added or removed.
   void OnDeviceAdded(DeviceInfoPtr device);
   void OnDeviceRemoved(std::string device_guid);
   void MaybeRunDeviceChangesCallback();
+  void OnPermissionCheckComplete(mojo::Array<DeviceInfoPtr> devices_added,
+                                 const std::set<std::string>& devices_removed,
+                                 mojo::Array<mojo::String> allowed_guids);
 
   mojo::StrongBinding<DeviceManager> binding_;

[Ken Rockot(use gerrit already), 2015/09/02 22:42:33]

as discussed offline, this can become a mojo::Binding and we can leave
DeviceManagerImpl in control of its own lifetime

[Ken Rockot(use gerrit already), 2015/09/02 23:07:18]

to preserve what was also just discussed offline, you want this to occur after
device_change_callbacks_ so the Binding is destroyed before pending response
callbacks.

Then you can ignore my comment about flushing callbacks in the dtor

[Reilly Grant (use Gerrit), 2015/09/02 23:58:19]

Done.

 
-  scoped_ptr<DeviceManagerDelegate> delegate_;
+  PermissionProviderPtr permission_provider_;
   scoped_refptr<base::SequencedTaskRunner> service_task_runner_;
 
   // If there are unfinished calls to GetDeviceChanges their callbacks
@@ -78,6 +81,11 @@ class DeviceManagerImpl : public DeviceManager {
   std::queue<GetDeviceChangesCallback> device_change_callbacks_;
   mojo::Array<DeviceInfoPtr> devices_added_;
   std::set<std::string> devices_removed_;
+  // To ensure that GetDeviceChangesCallbacks are called in the correct order
+  // only perform a single request to |permission_provider_| at a time.
+  bool permission_request_pending_ = false;
+  // The first notification is allowed to be empty. All others are not.
+  bool first_notification_ = true;
 
   // |helper_| is owned by the service thread and holds a weak reference
   // back to the device manager that created it.