Unfortunately here the Sendkeys are not working as it is contextual menu. The below is working fine.
_WebDriver=new FirefoxDriver();
_WebDriver.navigate().to("
http://www.gmail.com");
_WebDriver.manage().window().maximize();
Thread.sleep(2000);
_WebDriver.findElement(By.xpath("//*[@id='link-signup']/a")).click();
Thread.sleep(4000);
_WebDriver.findElement(By.xpath("//*[@id='BirthMonth']/div/div[2]")).click();
Thread.sleep(2000);
List<WebElement>ListOfMonths=_WebDriver.findElements(By.xpath("//*[@class='goog-menuitem-content']"));
JavascriptExecutor JSE=(JavascriptExecutor) _WebDriver;
for(WebElement Month : ListOfMonths)
{
System.out.println(Month.getText());
if(Month.getText().equalsIgnoreCase("August"))
{
JSE.executeScript("arguments[0].scrollIntoView(true)", Month);
Month.click();
break;