add case of merge inline info & modify ref test
auto merge of #1577 : ksh8281/servo/inline_add2, r=larsbergstrom

there is a issue when TextRunScanning.
this is for 
```
<span style="background:red;font-size:35px;border: black solid 15px">
        <span style="background:purple; 20px solid">
            <img src="test.jpeg" style="border:blue 30px solid;" />
        </span>
</span>
```
this case. left border of "img" is missing