Open Radar

 
Summary:
When setting secureTextEntry to NO (from YES) on a UITextFIeld with text in it, the textfield renders the font in a wrong font and add additional white space after the rendered text.

Steps to Reproduce:
1. Create a UITextField with secureTextEntry = YES
2. type some text in it
3. set secureTextEntry = NO while it is first responder

Expected Results:
- The text typed in becomes visible in the font specified in UITextField.font

Actual Results:
The text is shown in a font different than UITextField.font 

Regression:

Notes:
A workaround is to switch to a different font and back, that seems to kick the text renderer to update:
```
UIFont* font = textField.font;
textField.font = [font fontWithSize:font.pointSize+1]:
textField.font = font;
```