The Quick return design pattern is a feature that makes the action bar/split action bar to dissipate as a user begins scrolling down content, just to reappear as soon as the user starts scrolling up. The reason is to provide more screen real estate to the content, and not waste it on contextual controls that are not being used (since the user is scrolling). A live example of the implementation is available in this presentation.
Variations of the patter is used throughout Googles own applications, plus it's also used in facebook and Evernote to name a few. However, it's not utilized in the Gmail app, and I can't for the life of me figure out why.
Just like when browsing a Google search list, a user also browse their Gmail inbox. The possibility of providing the user with more screen real estate to show more items at once seems like a slam dunk, however no quick return has been introduced here.
Does anyone have any insight on this matter? Or can reason their way to the reason in a way that I seem incapable of?