code: function(serviceRegistry) {
  			this._serviceRegistry = serviceRegistry;
  			this._prefService = serviceRegistry.getService("orion.core.preference"); //$NON-NLS-1$
  
  			if (this._prefService) {
  				// Get the overrides from the preference store
  				this._getBindingOverrides().then(function(overrides) {
  					this._bindingOverrides = overrides;
  					
  					// Update all folks that are listening
  					this._updateBindingOverrides();
  				}.bind(this));
  	
  				// listen for changes from other pages
  				this._prefService.addEventListener("changed", function (e) {
  					if (e.namespace === "/KeyBindings") { //$NON-NLS-1$
  						// Refresh the binding overrides
  						this._getBindingOverrides().then(function(overrides) {
  							if (overrides.length > this._bindingOverrides.length) {
  								// handle any new changes
  								for (var i = this._bindingOverrides.length; i < overrides.length; i++) {
  									var override = overrides[i];
  									var bindingChangeEvent = {type: "bindingChanged", id: override.id, newBinding: override.newBinding,  //$NON-NLS-1$
  																prevBinding: override.prevBinding};
  									this.dispatchEvent(bindingChangeEvent);
  								}
  							}
  							this._bindingOverrides = overrides;
  						}.bind(this));
  					}
  				}.bind(this));
  			}
  		}
docs: Register the serviceRegistry. Use this gain access to any other services we need (i.e. the preferenceService)
  @param serviceRegistry {orion.serviceregistry.ServiceRegistry} the current service registry.