Roll opus 256783:289085

The only changes this picks up are:
https://codereview.chromium.org/450213003/
https://codereview.chromium.org/332413005/

BUG=124610
TBR=sergeyu

Review URL: https://codereview.chromium.org/464103002

Cr-Commit-Position: refs/heads/master@{#289236}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289236 0039d316-1c4b-4281-b951-d872f2087c98

DEPS

@@ -299,7 +299,7 @@ deps = {
     (Var("googlecode_url") % "pywebsocket") + "/trunk/src@790",
 
   "src/third_party/opus/src":
-    "/trunk/deps/third_party/opus@256783",
+    "/trunk/deps/third_party/opus@289085",
 
   "src/media/cdm/ppapi/api":
     "/trunk/deps/cdm@288172",

third_party/opus/README.chromium

@@ -10,3 +10,6 @@ This directory contains a copy of Opus library
 
 This library is used by Chrome Remote Desktop and WebRTC for audio stream
 encoding/decoding.
+
+Local changes:
+- merged http://git.xiph.org/?p=opus.git;a=commitdiff;h=e70faf98b0465e4f278c72ce2d7b4ad10221a2f2