Merge 117748 - Linear sub-rectangle scaler for use in Chromoting.

Merge 117748 - Linear sub-rectangle scaler for use in Chromoting.

This implementation re-uses the common row filter procedures, but is currently limited to a C horizontal interpolation procedure.

There's also plenty of scope for optimizing the new sub-rectangle scaler routine.

BUG=93451
TEST=media_unittests, remoting_unittests and manual verification of image quality of Chromoting sessions using fit-to-screen.


Review URL: http://codereview.chromium.org/8954003

TBR=wez@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=118602