Replace WebAudio MediaCodec usage with FFmpeg. A ~4x improvement.
Now that ffmpeg is linked in for project spitzer (issue 507834) we
can use it for audio decoding on Android; this provides a more
secure (all decoding in the renderer) and faster decoding experience
for WebAudio users.
Using the demo page from the linked bug, the improvements are:
apk size: -2162 bytes
aac decode: 12.9 seconds -> 3.7 seconds (~3.5x speedup)
ogg decode: 15.7 seconds -> 3.8 seconds (~4.1x speedup)
BUG=424174, 570711, 570788
TEST=existing layout tests all pass.
Review URL: https://codereview.chromium.org/1565623002
Cr-Commit-Position: refs/heads/master@{#367881}
21 files changed
