Blink implementation of PushManager#hasPermission()

public/platform/WebPushClient.h

Index: public/platform/WebPushClient.h
diff --git a/public/platform/WebPushClient.h b/public/platform/WebPushClient.h
index 7189fcd363fb8834088cdc27c4ad2be06e71c884..71be9dc8b59f66d4d8c177534219e048355c5cd5 100644
--- a/public/platform/WebPushClient.h
+++ b/public/platform/WebPushClient.h
@@ -7,6 +7,7 @@
 
 #include "public/platform/WebCallbacks.h"
 #include "public/platform/WebPushError.h"
+#include "public/platform/WebPushPermissionStatus.h"
 
 namespace blink {
 
@@ -14,6 +15,7 @@ class WebServiceWorkerProvider;
 struct WebPushRegistration;
 
 typedef WebCallbacks<WebPushRegistration, WebPushError> WebPushRegistrationCallbacks;
+typedef WebCallbacks<WebPushPermissionStatus, void> WebPushPermissionCallback;
 
 class WebPushClient {
 public:
@@ -22,6 +24,10 @@ public:
     // Ownership of the WebPushRegistrationCallbacks is transferred to the
     // client. Ownership of the WebServiceWorkerProvider is not transferred.
     virtual void registerPushMessaging(WebPushRegistrationCallbacks*, WebServiceWorkerProvider*) { }
+
+    // Ownership of the WebPushPermissionCallback is transferred to the
+    // client. Ownership of the WebServiceWorkerProvider is not transferred.
+    virtual void getPermissionStatus(WebPushPermissionCallback*, WebServiceWorkerProvider*) { }
 };
 
 } // namespace blink