Implement basic mojo Permission service and use it for Geolocation.

content/browser/frame_host/render_frame_host_impl.h

Index: content/browser/frame_host/render_frame_host_impl.h
diff --git a/content/browser/frame_host/render_frame_host_impl.h b/content/browser/frame_host/render_frame_host_impl.h
index 9bfcc060b12d0fd552ffdda849f0a6a33ddb3764..05d04fb2feccc6a55e30e0dd52de5388340624b9 100644
--- a/content/browser/frame_host/render_frame_host_impl.h
+++ b/content/browser/frame_host/render_frame_host_impl.h
@@ -53,6 +53,7 @@ class CrossProcessFrameConnector;
 class CrossSiteTransferringRequest;
 class FrameTree;
 class FrameTreeNode;
+class PermissionServiceContext;
 class RenderFrameHostDelegate;
 class RenderFrameProxyHost;
 class RenderProcessHost;
@@ -605,6 +606,9 @@ class CONTENT_EXPORT RenderFrameHostImpl
   // response once it has started.
   scoped_ptr<StreamHandle> stream_handle_;
 
+  // Context shared for each PermissionService instance created for this RFH.
+  scoped_ptr<PermissionServiceContext> permission_service_context_;
+
   // NOTE: This must be the last member.
   base::WeakPtrFactory<RenderFrameHostImpl> weak_ptr_factory_;