Changes to upgrade libvpx to head of master.

Also aligns libvpx build system in WebRTC with Chromium's.

BUG=

Review URL: https://webrtc-codereview.appspot.com/708008

git-svn-id: http://webrtc.googlecode.com/svn/trunk@2623 4adac7df-926f-26a2-2b94-8c16560cd09d

DEPS

diff --git a/DEPS b/DEPS
index 3031a22..6d778ba 100644
--- a/DEPS
+++ b/DEPS
@@ -48,7 +48,7 @@
     From("chromium_deps", "src/third_party/libjpeg_turbo"),
 
   "third_party/libvpx/source/libvpx":
-    "http://git.chromium.org/webm/libvpx.git@cab6ac16",
+    "http://git.chromium.org/webm/libvpx.git@69babd3",
 
   "third_party/libyuv":
     (Var("googlecode_url") % "libyuv") + "/trunk@255",
@@ -111,6 +111,15 @@
                "--mac-only"],
   },
   {
+    # Update the cygwin mount on Windows.
+    # This is necessary to get the correct mapping between e.g. /bin and the
+    # cygwin path on Windows. Without it we can't run bash scripts in actions.
+    # Ideally this should be solved in "pylib/gyp/msvs_emulation.py".
+    "pattern": ".",
+    "action": ["python", Var("root_dir") + "/build/win/setup_cygwin_mount.py",
+               "--win-only"],
+  },
+  {
     # Download test resources, i.e. video and audio files. If the latest
     # version is already downloaded, this takes zero seconds to run.
     # If a newer version or no current download exists, it will download