Bump chromium deps to 260824 which is lkgr for improved mobile support.

BUG=none
TESTED=try bots
R=tpsiaki@google.com

Review URL: https://webrtc-codereview.appspot.com/10999005

git-svn-id: http://libyuv.googlecode.com/svn/trunk@996 16f28f9a-4ce2-e073-06de-1de4eb20be90

DEPS

@@ -14,7 +14,7 @@ vars = {
   "chromium_trunk" : "http://src.chromium.org/svn/trunk",
   # chrome://version/ for revision of canary Chrome.
   # http://chromium-status.appspot.com/lkgr is a last known good revision.
-  "chromium_revision": "255773",
+  "chromium_revision": "260824",
 }
 
 # NOTE: Prefer revision numbers to tags for svn deps. Use http rather than