Implement basic mojo Permission service and use it for Geolocation.

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright (c) 2012 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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 48 matching lines @@
 #include "content/browser/indexed_db/indexed_db_dispatcher_host.h"
 #include "content/browser/loader/resource_message_filter.h"
 #include "content/browser/loader/resource_scheduler_filter.h"
 #include "content/browser/media/capture/audio_mirroring_manager.h"
 #include "content/browser/media/media_internals.h"
 #include "content/browser/media/midi_host.h"
 #include "content/browser/message_port_message_filter.h"
 #include "content/browser/mime_registry_message_filter.h"
 #include "content/browser/mojo/mojo_application_host.h"
 #include "content/browser/notifications/notification_message_filter.h"
+#include "content/browser/permissions/permission_service_context.h"
+#include "content/browser/permissions/permission_service_impl.h"
 #include "content/browser/profiler_message_filter.h"
 #include "content/browser/push_messaging/push_messaging_message_filter.h"
 #include "content/browser/quota_dispatcher_host.h"
 #include "content/browser/renderer_host/clipboard_message_filter.h"
 #include "content/browser/renderer_host/database_message_filter.h"
 #include "content/browser/renderer_host/file_utilities_message_filter.h"
 #include "content/browser/renderer_host/gamepad_browser_message_filter.h"
 #include "content/browser/renderer_host/gpu_message_filter.h"
 #include "content/browser/renderer_host/media/audio_input_renderer_host.h"
 #include "content/browser/renderer_host/media/audio_renderer_host.h"
@@ skipping 789 matching lines @@
 #if defined(OS_ANDROID)
   AddFilter(new ScreenOrientationMessageFilterAndroid());
 #endif
   AddFilter(new GeofencingDispatcherHost(
       storage_partition_impl_->GetGeofencingManager()));
 }
 
 void RenderProcessHostImpl::RegisterMojoServices() {
   mojo_application_host_->service_registry()->AddService(
       base::Bind(&device::BatteryMonitorImpl::Create));
+
+  scoped_ptr<PermissionServiceContext> permission_service_context(
+    new PermissionServiceContext(nullptr));

[nasko, 2014/11/13 23:57:38]

Why is it valid to register a context with null RFH?

[mlamouri (slow - plz ping), 2014/11/14 00:16:33]

The service on the RenderProcessHost can't show any UI (RFH is needed for that)
but we still want a service to be available for the rest of the features it
provides.

I've decided to pass a null RFH so the service always have a context but will
have to check whether its context has a RFH/WebContents. Does that sound sane to
you? Alternatively, I could pass a null context.

[nasko, 2014/11/14 00:42:50]

I like always having a context and it including the indicators on how it should
be used. I think what you have here is fine, it was more of me trying to get the
bigger picture of how this works.

+  mojo_application_host_->service_registry()->AddService(
+      base::Bind(&PermissionServiceImpl::Create,
+                 base::Passed(&permission_service_context)));
 }
 
 int RenderProcessHostImpl::GetNextRoutingID() {
   return widget_helper_->GetNextRoutingID();
 }
 
 void RenderProcessHostImpl::ResumeDeferredNavigation(
     const GlobalRequestID& request_id) {
   widget_helper_->ResumeDeferredNavigation(request_id);
 }
@@ skipping 1349 matching lines @@
 
 void RenderProcessHostImpl::DecrementWorkerRefCount() {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   DCHECK_GT(worker_ref_count_, 0);
   --worker_ref_count_;
   if (worker_ref_count_ == 0)
     Cleanup();
 }
 
 }  // namespace content