Submitting lines to a specific buffer

[lopcode]

Once viewing a buffer, the user should be able to tap on a text input field, and submit content to the buffer.

A "Send" button should be present near text input field. The text input field should automatically expand in height to fit the amount of text, up to a maximum of 5 lines, and then the text content should scroll so as to not take up more screen space. Hangouts does this particularly well.