Move libvpx from DEPS to src

third_party/libvpx/source/libvpx/vp9/encoder/vp9_ethread.h

Index: third_party/libvpx/source/libvpx/vp9/encoder/vp9_ethread.h
diff --git a/third_party/libvpx/source/libvpx/vp9/encoder/vp9_ethread.h b/third_party/libvpx/source/libvpx/vp9/encoder/vp9_ethread.h
new file mode 100644
index 0000000000000000000000000000000000000000..e87c50bc7125bc97fb90ad4464d99f5c272eeb56
--- /dev/null
+++ b/third_party/libvpx/source/libvpx/vp9/encoder/vp9_ethread.h
@@ -0,0 +1,25 @@
+/*
+ *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef VP9_ENCODER_VP9_ETHREAD_H_
+#define VP9_ENCODER_VP9_ETHREAD_H_
+
+struct VP9_COMP;
+struct ThreadData;
+
+typedef struct EncWorkerData {
+  struct VP9_COMP *cpi;
+  struct ThreadData *td;
+  int start;
+} EncWorkerData;
+
+void vp9_encode_tiles_mt(struct VP9_COMP *cpi);
+
+#endif  // VP9_ENCODER_VP9_ETHREAD_H_