Implement basic mojo Permission service and use it for Geolocation.

content/browser/permissions/permission_service_context.h

+// Copyright 2014 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.
+
+#include "base/macros.h"
+#include "content/public/browser/web_contents_observer.h"
+
+#ifndef CONTENT_BROWSER_PERMISSIONS_PERMISSION_SERVICE_CONTEXT_H_
+#define CONTENT_BROWSER_PERMISSIONS_PERMISSION_SERVICE_CONTEXT_H_
+
+namespace content {
+
+class PermissionServiceImpl;
+class RenderFrameHost;
+
+// Provides information to a PermissionService. It is used by the
+// PermissionService to handle request permission UI.
+// The RenderFrameHost creates an instance when setting up the Permission mojo
+// service and then passes ownership to the service.
+class PermissionServiceContext : public WebContentsObserver {
+ public:
+  explicit PermissionServiceContext(RenderFrameHost* render_frame_host);
+  virtual ~PermissionServiceContext();
+
+  // WebContentsObserver
+  void RenderFrameDeleted(RenderFrameHost* render_frame_host) override;
+  void DidNavigateAnyFrame(RenderFrameHost* render_frame_host,
+                           const LoadCommittedDetails& details,
+                           const FrameNavigateParams& params) override;
+
+  RenderFrameHost* render_frame_host();
+
+  void set_service(PermissionServiceImpl* service);

[qsr, 2014/11/14 09:20:26]

This seems weird. There is a single context for multiple PermissionServiceImpl.

[mlamouri (slow - plz ping), 2014/11/14 11:37:11]

That's not the model I had in mind. Contrary to the Geolocation service, I
really need to know about the RFH for the permissions to be able to dismiss
permissions prompts that come from a frame when it is navigated. I wonder if I
then need one context per service or simply pass the RFH to the service?

+
+ private:
+  RenderFrameHost* render_frame_host_;
+  PermissionServiceImpl* service_;
+
+  DISALLOW_COPY_AND_ASSIGN(PermissionServiceContext);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_PERMISSIONS_PERMISSION_SERVICE_CONTEXT_H_