I wrote a trigger and class to call out to the Google Geo location api and return the latitude and longitude then update a geolocation field on a location record.  Everything seems to work with the API I can see from Debug Logs that the class gets the location but it stops short of updating the record.  My trigger and class are below.

CLASS

public class FslLocationGeocodeAddress {
    // static variable to determine if geocoding has already occurred
    private static Boolean geocodingCalled = false;
    // wrapper method to prevent calling futuremethods from an existing future context
    public static void DoAddressGeocode(id locationId) {
        if(geocodingCalled || System.isFuture()) {
            System.debug(LoggingLevel.WARN,'***Address Geocoding Future Method Already Called - Aborting...');
            return;
        }
        // if not being called from future context, geocode the address
        geocodingCalled = true;
        geocodeAddress(locationId);
    }
    
    
    // we need a future method to call Google Geocoding API from Salesforce
    @future (callout=true)
    static private void geocodeAddress(id locationId)
    { 
        // Key for Google Maps Geocoding API
        String geocodingKey = 'AIzaSyDsXhgOWw8h98l2rWnOcRy4j8_l8Evx3Ms';
        // get the passed in address 
        CKSW_BASE__Location__c geoLocation = [SELECT Street_Address__c,  City__c, State_Providence__c, Country__c, Zipcode__c  FROM CKSW_BASE__Location__c WHERE id = :locationId];
        //check that we have enough information to geocode the address
        if((geoLocation.Street_Address__c == null) || (geoLocation.City__c == null)) {
            System.debug(LoggingLevel.WARN,'Insufficient Data to Geocode Address');
            return;
        }
        //create a string for the address to pass to Google Geocoding API
        String geoAddress = '';
        if(geoLocation.Street_Address__c != null)
            geoAddress += geoLocation.Street_Address__c + ', ';
        if(geoLocation.City__c != null)
            geoAddress += geoLocation.City__c + ', ';
        if(geoLocation.State_Providence__c != null)
            geoAddress+= geoLocation.State_Providence__c + ', ';
        if(geoLocation.Country__c != null)
            geoAddress+= geoLocation.Country__c + ', ';
        if(geoLocation.Zipcode__c != null)
            geoAddress+= geoLocation.Zipcode__c;
        System.debug('GeoAddress is set '+geoAddress);
        //encode the string so we can pass it as part of URL
        geoAddress= EncodingUtil.urlEncode(geoAddress, 'UTF-8');
        //build and make the callout to the Geocoding API
        Http http = new Http();
        HttpRequest request = new HttpRequest();
        request.setEndpoint('https://maps.googleapis.com/maps/api/geocode/json?address='+geoAddress + '&key=' + geocodingKey + '&sensor=false');
        request.setMethod('GET');
        request.setTimeout(60000);
        try {
            //make the http callout
            HttpResponse response = http.send(request);
            System.debug('The Http response is '+response);
            string body = response.getBody();
            System.debug('The response body is' + body);
            //parse JSON to extract co-ordinates
            JSONParser responseParser = JSON.createParser(response.getBody());
            system.debug('The response parser is'+responseParser);
            //initialize co-ordinates
            double latitude = null;
            double longitude = null;
            system.debug('Next token prior to the while nextToken != Null is '+responseParser.nextToken());
            //while loop 1
            while(responseParser.nextToken() != null ) {
                if((responseParser.getCurrentToken() == JSONToken.FIELD_NAME) && (responseParser.getText() == 'location')) {
                    system.debug('If condition true');
                    system.debug('Current Token = '+responseParser.getCurrentToken()+' Current  text = '+responseParser.getText());
                    responseParser.nextToken();
                    system.debug('Next Token = '+responseParser.nextToken());
                    while (responseParser.nextToken() != JSONToken.END_OBJECT) {
                        system.debug('While condition 2 true');
                        String locationText = responseParser.getText();
                        latitude = responseParser.getDoubleValue();
                        system.debug('responseParser.getText() = '+responseParser.getText());
                        system.debug('responseParser.getDoubleValue() = '+responseParser.getDoubleValue());
                        latitude = responseParser.getDoubleValue();
                        system.debug(latitude);
                        responseParser.nextToken(); 
                        system.debug('responseParser.nextToken() = '+responseParser.nextToken());
                        system.debug('text ='+responseParser.getText());
                        system.debug('responseParser.getDoubleValue() = '+responseParser.getDoubleValue());
                        longitude = responseParser.getDoubleValue();
                        system.debug(longitude);
                        
                    }
                }
            }
            system.debug('Latitude = '+latitude);
            system.debug('Longitude = '+longitude);
            
           if (longitude != null && latitude != null){
                system.debug('latitude != null');                
                geoLocation.Geolocation__Latitude__s = latitude;
                system.debug('Latitude is '+geoLocation.Geolocation__Latitude__s);
                geoLocation.Geolocation__Longitude__s = longitude;
                system.debug('Longitude is '+geoLocation.Geolocation__Longitude__s);
                system.debug('geoLocation id '+geoLocation.Geolocation__c);
                update Geolocation;
            }

        } catch(Exception e) {
            System.debug(LoggingLevel.ERROR, 'Error Geocoding Address - ' + e.getMessage());
        }
    }
}

TRIGGER 
trigger FslLocationGeocodeAddress on CKSW_BASE__Location__c (after insert, after update) {
    
    //bulkify trigger in case of multiple locations
    for(CKSW_BASE__Location__c location : trigger.new) {
        
        //check if Billing Address has been updated
        Boolean addressChangedFlag = false;
        if(Trigger.isUpdate) {
            CKSW_BASE__Location__c oldLocation = Trigger.oldMap.get(location.Id);
            if((location.Street_Address__c != oldLocation.Street_Address__c) || (location.City__c != oldLocation.City__c) || 
               (location.Country__c != oldLocation.Country__c) || (location.Zipcode__c != oldLocation.Zipcode__c)) {
                   addressChangedFlag = true;                   
                   System.debug(LoggingLevel.DEBUG, '***Address changed for - ' + oldLocation.Name);
               }
        }
        // if address is null or has been changed, geocode it
        if((location.Geolocation__Latitude__s == null && location.Geolocation__Longitude__s == null) || (addressChangedFlag == true)) {
            System.debug(LoggingLevel.DEBUG,'***Geocoding CKSW_BASE__Location__c - ' + location.Name);
            FslLocationGeocodeAddress.DoAddressGeocode(location.id);
        
        }
    }
}