Adds a way to determine id of content handler that created app

mojo/application/public/cpp/lib/service_registry.cc

 // 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 "mojo/application/public/cpp/lib/service_registry.h"
 
+#include "base/bind.h"
 #include "base/logging.h"
 #include "mojo/application/public/cpp/application_connection.h"
 #include "mojo/application/public/cpp/service_connector.h"
 
 namespace mojo {
 namespace internal {
 
 ServiceRegistry::ServiceRegistry(
     const std::string& connection_url,
     const std::string& remote_url,
     ServiceProviderPtr remote_services,
     InterfaceRequest<ServiceProvider> local_services,
     const std::set<std::string>& allowed_interfaces)
     : connection_url_(connection_url),
       remote_url_(remote_url),
       local_binding_(this),
       remote_service_provider_(remote_services.Pass()),
       allowed_interfaces_(allowed_interfaces),
       allow_all_interfaces_(allowed_interfaces_.size() == 1 &&
                             allowed_interfaces_.count("*") == 1),
+      content_handler_id_(0u),
+      is_content_handler_id_valid_(false),
       weak_factory_(this) {
   if (local_services.is_pending())
     local_binding_.Bind(local_services.Pass());
 }
 
 ServiceRegistry::ServiceRegistry()
     : local_binding_(this),
       allow_all_interfaces_(true),
       weak_factory_(this) {
 }
 
 ServiceRegistry::~ServiceRegistry() {
 }
 
+Shell::ConnectToApplicationCallback
+ServiceRegistry::GetConnectToApplicationCallback() {
+  return base::Bind(&ServiceRegistry::OnGotContentHandlerID,
+                    weak_factory_.GetWeakPtr());
+}
+
 void ServiceRegistry::SetServiceConnector(ServiceConnector* connector) {
   service_connector_registry_.set_service_connector(connector);
 }
 
 bool ServiceRegistry::SetServiceConnectorForName(
     ServiceConnector* service_connector,
     const std::string& interface_name) {
   if (allow_all_interfaces_ ||
       allowed_interfaces_.count(interface_name)) {
     service_connector_registry_.SetServiceConnectorForName(service_connector,
                                                            interface_name);
     return true;
   }
   LOG(WARNING) << "CapabilityFilter prevented connection to interface: " <<
       interface_name;
   return false;
 }
 
 ServiceProvider* ServiceRegistry::GetLocalServiceProvider() {
   return this;
 }
 
 void ServiceRegistry::SetRemoteServiceProviderConnectionErrorHandler(
     const Closure& handler) {
   remote_service_provider_.set_connection_error_handler(handler);
 }
 
+bool ServiceRegistry::GetContentHandlerID(uint32_t* content_handler_id) {
+  if (!is_content_handler_id_valid_)
+    return false;
+
+  *content_handler_id = content_handler_id_;
+  return true;
+}
+
+void ServiceRegistry::AddContentHandlerIDCallback(const Closure& callback) {
+  if (is_content_handler_id_valid_) {
+    callback.Run();
+    return;
+  }
+  content_handler_id_callbacks_.push_back(callback);
+}
+
 base::WeakPtr<ApplicationConnection> ServiceRegistry::GetWeakPtr() {
   return weak_factory_.GetWeakPtr();
 }
 
 void ServiceRegistry::RemoveServiceConnectorForName(
     const std::string& interface_name) {
   service_connector_registry_.RemoveServiceConnectorForName(interface_name);
   if (service_connector_registry_.empty())
     remote_service_provider_.reset();
 }
 
 const std::string& ServiceRegistry::GetConnectionURL() {
   return connection_url_;
 }
 
 const std::string& ServiceRegistry::GetRemoteApplicationURL() {
   return remote_url_;
 }
 
 ServiceProvider* ServiceRegistry::GetServiceProvider() {
   return remote_service_provider_.get();
 }
 
+void ServiceRegistry::OnGotContentHandlerID(uint32_t content_handler_id) {
+  DCHECK(!is_content_handler_id_valid_);
+  is_content_handler_id_valid_ = true;
+  content_handler_id_ = content_handler_id;
+  std::vector<Closure> callbacks;
+  callbacks.swap(content_handler_id_callbacks_);
+  for (auto callback : callbacks)
+    callback.Run();
+}
+
 void ServiceRegistry::ConnectToService(const mojo::String& service_name,
                                        ScopedMessagePipeHandle client_handle) {
   service_connector_registry_.ConnectToService(this, service_name,
                                                client_handle.Pass());
 }
 
 }  // namespace internal
 }  // namespace mojo