Scale buffer to fit the layer boundary

Skia render engine incorrectly renders garbled video layer, due to lack of scaling to the layer's boundary.

Bug: 171404534
Test: adb root; adb shell setprop debug.renderengine.backend skiagl; adb shell stop; adb shell start
then take a screenshot from playing this video inside web browser with this url: https://www.reddit.com/r/Awww/comments/jjkvdm/if_a_cat_loves_you_sure_you_are_a_lovely_person/

Change-Id: I67da06f384345e300380f34afe1b60cfa2b5fe0b