Implement PermissionService::GetNextPermissionChange.

content/browser/permissions/permission_service_impl.h

Index: content/browser/permissions/permission_service_impl.h
diff --git a/content/browser/permissions/permission_service_impl.h b/content/browser/permissions/permission_service_impl.h
index 57f1bfd48b1fa166b0c40c4261c6ec844ab6a4cf..57c3876f045e8a66b239ccda8e8e33b8031f6f19 100644
--- a/content/browser/permissions/permission_service_impl.h
+++ b/content/browser/permissions/permission_service_impl.h
@@ -42,6 +42,11 @@ class PermissionServiceImpl : public mojo::InterfaceImpl<PermissionService> {
   };
   typedef IDMap<PendingRequest, IDMapOwnPointer> RequestsMap;
 
+  struct PendingSubscription {
+    int subscription_id;
+  };
+  typedef IDMap<PendingSubscription, IDMapOwnPointer> SubscriptionsMap;
+
   // PermissionService.
   void HasPermission(
       PermissionName permission,
@@ -56,19 +61,32 @@ class PermissionServiceImpl : public mojo::InterfaceImpl<PermissionService> {
       PermissionName permission,
       const mojo::String& origin,
       const mojo::Callback<void(PermissionStatus)>& callback) override;
+  void GetNextPermissionChange(
+      PermissionName permission,
+      const mojo::String& origin,
+      PermissionStatus last_known_status,
+      const mojo::Callback<void(PermissionStatus)>& callback) override;
 
   // mojo::InterfaceImpl.
   void OnConnectionError() override;
 
   void OnRequestPermissionResponse(
-    const mojo::Callback<void(PermissionStatus)>& callback,
-    int request_id,
-    PermissionStatus status);
+      const mojo::Callback<void(PermissionStatus)>& callback,
+      int request_id,
+      PermissionStatus status);
+
+  PermissionStatus GetPermissionStatus(PermissionName permission,
+                                       const GURL& origin);
+  PermissionStatus GetPermissionStatus(PermissionType type, const GURL& origin);
+  void ResetPermissionStatus(PermissionType type, const GURL& origin);
 
-  PermissionStatus GetPermissionStatus(PermissionType type, GURL origin);
-  void ResetPermissionStatus(PermissionType type, GURL origin);
+  void OnPermissionStatusChanged(
+      const mojo::Callback<void(PermissionStatus)>& callback,
+      int pending_subscription_id,
+      PermissionStatus status);
 
   RequestsMap pending_requests_;
+  SubscriptionsMap pending_subscriptions_;
   // context_ owns |this|.
   PermissionServiceContext* context_;
   base::WeakPtrFactory<PermissionServiceImpl> weak_factory_;