Sync libvpx and its gyp wrapper from Chromium.

TBR=kjellander
BUG=webrtc:1213

Review URL: https://webrtc-codereview.appspot.com/1096007

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3505 4adac7df-926f-26a2-2b94-8c16560cd09d

DEPS

diff --git a/DEPS b/DEPS
index 5b94e08..6086f4e 100644
--- a/DEPS
+++ b/DEPS
@@ -51,8 +51,8 @@
   "third_party/libjpeg_turbo":
     From("chromium_deps", "src/third_party/libjpeg_turbo"),
 
-  "third_party/libvpx/source/libvpx":
-    "http://git.chromium.org/webm/libvpx.git@7a09f6b8",
+  "third_party/libvpx":
+    Var("chromium_trunk") + "/deps/third_party/libvpx@180104",
 
   "third_party/libyuv":
     (Var("googlecode_url") % "libyuv") + "/trunk@540",