[Merge to M44] Chromium changes to statically link ffmpeg.

[Merge to M44] Chromium changes to statically link ffmpeg.

Motivations:
1. Eliminates a large number of windows crashes hit while loading the DLL (see bugs)
2. Reducing the size of binary (about 400KB on linux, about 265KB on 32bit windows) due to dead-code elimination
3. Simplifying media library initialization (Remove bool-ness, it just works)

Licensing:
We've audited all the licenses for the files we actually use and have the green light from legal as long as we include the license text in the credits.

TBR=thomasvl@chromium.org, dalecurtis@chromium.org, enne@chromium.org, grt@chromium.org, gunsch@chromium.org, isherman@chromium.org, jamiewalch@chromium.org, jochen@chromium.org, maruel@chromium.org, mmoss@google.com, phajdan.jr@chromium.org, sergeyu@chromium.org, sky@chromium.org
BUG=435455, 429131, 441908
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Original Review URL:
https://codereview.chromium.org/1141703002

(cherry picked from commit fd11b3c3aa6730ae1f024811b61913cd63f9d39a - refs/heads/master@{#333423})

Committed: https://chromium.googlesource.com/chromium/src/+/ab31fe6077d2ba3ede9a302d9ef4554363c9a939

[chcunningham, 2015-06-17 22:58:55]

chcunningham@chromium.org changed reviewers:
+ dalecurtis@chromium.org, enne@chromium.org, grt@chromium.org,
gunsch@chromium.org, isherman@chromium.org, jamiewalch@chromium.org,
jochen@chromium.org, maruel@chromium.org, mmoss@google.com,
phajdan.jr@chromium.org, sergeyu@chromium.org, sky@chromium.org,
thomasvl@chromium.org

[chcunningham, 2015-06-17 23:00:39]

Merging back. Dale will commit since I can't :(.

[DaleCurtis, 2015-06-17 23:03:33]

Committed patchset #1 (id:1) manually as
ab31fe6077d2ba3ede9a302d9ef4554363c9a939 (presubmit successful).