Implement PermissionService::GetNextPermissionChange.

content/child/permissions/permission_manager.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_CHILD_PERMISSIONS_PERMISSION_MANAGER_H_
+#define CONTENT_CHILD_PERMISSIONS_PERMISSION_MANAGER_H_
+
+#include <string>
+
+#include "base/compiler_specific.h"
+#include "base/id_map.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/common/permission_service.mojom.h"
+#include "third_party/WebKit/public/platform/modules/permissions/WebPermissionClient.h"
+
+namespace content {
+
+class ServiceRegistry;
+
+// The PermissionManager is a layer between Blink and the Mojo PermissionService
+// It implements blink::WebPermissionClient. It is being used from workers and
+// frames independently. When called outside of the main thread,
+// QueryPermissionForWorker is meant to be called. It will handle the thread
+// jumping.
+class PermissionManager : public blink::WebPermissionClient {
+ public:
+  PermissionManager(ServiceRegistry& service_registry);

[Bernhard Bauer, 2015/03/23 10:20:44]

explicit

+  virtual ~PermissionManager();
+
+  // blink::WebPermissionClient implementation.
+  virtual void queryPermission(blink::WebPermissionType type,
+                               const blink::WebURL& origin,
+                               blink::WebPermissionQueryCallback* callback);
+
+  void QueryPermissionForWorker(blink::WebPermissionType type,
+                                const std::string& origin,
+                                blink::WebPermissionQueryCallback* callback,
+                                int worker_thread_id);
+
+ protected:

[Bernhard Bauer, 2015/03/23 10:20:44]

Why protected? Is this class meant to be subclassed?

+  void QueryPermissionInternal(blink::WebPermissionType type,
+                               const std::string& origin,
+                               blink::WebPermissionQueryCallback* callback,
+                               int worker_thread_id);
+
+  void OnQueryPermission(int request_id, PermissionStatus status);
+
+  // Called from the main thread in order to run the callback in the thread it
+  // was created on.
+  static void RunCallbackOnWorkerThread(

[Bernhard Bauer, 2015/03/23 10:20:44]

You could move this to an anonymous namespace in the .cc file.

+      blink::WebPermissionQueryCallback* callback,
+      scoped_ptr<blink::WebPermissionStatus> status);
+
+  // Saves some basic information about the callback in order to be able to run
+  // it in the right thread.
+  class CallbackInformation {

[Bernhard Bauer, 2015/03/23 10:20:44]

Can you only forward-declare this class here?

Also, types should go first in each section.

+   public:
+    CallbackInformation(blink::WebPermissionQueryCallback* callback,
+                        int worker_thread_id);
+    ~CallbackInformation();
+
+    blink::WebPermissionQueryCallback* callback() const;
+    int worker_thread_id() const;
+
+    blink::WebPermissionQueryCallback* ReleaseCallback();
+
+   private:
+    scoped_ptr<blink::WebPermissionQueryCallback> callback_;
+    int worker_thread_id_;
+
+    DISALLOW_COPY_AND_ASSIGN(CallbackInformation);
+  };
+  using CallbackMap = IDMap<CallbackInformation, IDMapOwnPointer>;
+  CallbackMap pending_callbacks_;
+
+  PermissionServicePtr permission_service_;
+
+  DISALLOW_COPY_AND_ASSIGN(PermissionManager);
+};
+
+}  // namespace content
+
+#endif // CONTENT_CHILD_PERMISSIONS_PERMISSION_MANAGER_H_