Bug 919129. Fix nsLayoutUtils::UpdateImageVisibilityForFrame so that it doesn't expand the image rect so much by replacing it with the scroll port rect. r=matspal
Backed out 6 changesets (bug 881804) for frequent Android reftest and jsreftest timeouts

Backed out changeset 61972f55702b (bug 881804)
Backed out changeset 0a24b77d4ffb (bug 881804)
Backed out changeset 9fbcf4c3ab2b (bug 881804)
Backed out changeset 2d35068ec2f5 (bug 881804)
Backed out changeset 757790e5cd9f (bug 881804)
Backed out changeset d8a172fa4b20 (bug 881804)