[Cherry pick of b0e89dcc1d8c1c2f9f7ffb45e8609cdb4a68104b to M39.]

Fix image filters for PDF backend.

Currently, the PDF backend does not support image filters (since PDF
does not have that functionality), so it simply removes them. This is
causing Chrome print preview to render incorrectly (see bug). The fix
here is to fall back to a raster device for image filters, as we used
to do in Blink. The resulting bitmap will be drawn to the destination
device as a normal main-memory-backed bitmap.

Note: this change invalidates the PDF results of all GMs containing
image filters (since they'll actually be rendered).

BUG=422144
TBR=reed@google.com

Review URL: https://codereview.chromium.org/644323006

Review URL: https://codereview.chromium.org/679083004
Update fontMgr to take list of bcp47 language tags.

This will enable clients to pass more than one bcp47 tag to ensure
that the most appropriate font is selected.

BUG=chromium:422180

Review URL: https://codereview.chromium.org/670243002

Cherry-pick: c20386e3937d3d398ac9b35f9c7d997e972ade98
Cherry-pick: 4aa75b798049741f214aac4a9ed959aa46d54d7e
Cherry-pick: 5f6094a1eb9bf5bb9fd17ada84a5763de2853eff
Approval: https://code.google.com/p/chromium/issues/detail?id=422180#c32