link localaudiosource into both sides for split_link

link localaudiosource into both sides for split_link

For constants. File here for reference:

https://code.google.com/p/chromium/codesearch#chromium/src/third_party/libjingle/source/talk/app/webrtc/localaudiosource.cc&q=kHighpassfilter&sq=package:chromium&type=cs&l=50

and doesn't look like there's any sneaky statics/globals going on.

R=cpu@chromium.org
BUG=237249
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=201351

[cpu_(ooo_6.6-7.5), 2013-05-21 20:33:57]

lgtm

[scottmg, 2013-05-21 20:35:53]

Committed patchset #1 manually as r201351 (presubmit successful).