To reproduce
- Open http://www.tinymce.com/tryit/full.php
- Clear the editing area
- Add two lines of text, for example, "Line1" and "Line2"
- Set the style of the first line to "Heading 1"
- Go to the end of the first line and hit DELETE

In all major browsers, the result will be a single line formatted as "Heading 1" with the following HTML representation:

    <h1>Line1Line2</h1>

In WebView, the result will be a single line consisting of two words, one formatted as "Heading 1" and the other formatted as "Paragraph", with the following HTML representation:

    <h1>Line1<span class="Apple-style-span" style="font-family: Dialog; font-weight: normal; font-size: medium;"></span></h1>
    <p style="display: inline !important;">Line2</p>

This is a TinyMCE-specific part of the problem reported in RT-16931