in the change for TV-634, an assumption was made that the clip in the graphics context for the backbuffer would contain the dirty region rectangle.
This change is in ES2SwapChain.java.

A more proper long term solution would be the explicit sharing of the dirty region rect (passing it to ES2SwapChain for the swap).

Look for the comment:

  65 // Note that we are using a bit of a cheat to get the dirty region
  66 // by asking for the clip rect of the last graphics we gave out
  67 // for the back buffer.