Move libvpx from DEPS to src

third_party/libvpx/source/libvpx/vp9/encoder/vp9_treewriter.h

Index: third_party/libvpx/source/libvpx/vp9/encoder/vp9_treewriter.h
diff --git a/third_party/libvpx/source/libvpx/vp9/encoder/vp9_treewriter.h b/third_party/libvpx/source/libvpx/vp9/encoder/vp9_treewriter.h
new file mode 100644
index 0000000000000000000000000000000000000000..4a76d87cdfea5fa72a1133bade4f36ae0aa44b7c
--- /dev/null
+++ b/third_party/libvpx/source/libvpx/vp9/encoder/vp9_treewriter.h
@@ -0,0 +1,51 @@
+/*
+ *  Copyright (c) 2010 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_TREEWRITER_H_
+#define VP9_ENCODER_VP9_TREEWRITER_H_
+
+#include "vp9/encoder/vp9_writer.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+void vp9_tree_probs_from_distribution(vp9_tree tree,
+                                      unsigned int branch_ct[ /* n - 1 */ ][2],
+                                      const unsigned int num_events[ /* n */ ]);
+
+struct vp9_token {
+  int value;
+  int len;
+};
+
+void vp9_tokens_from_tree(struct vp9_token*, const vp9_tree_index *);
+
+static INLINE void vp9_write_tree(vp9_writer *w, const vp9_tree_index *tree,
+                                  const vp9_prob *probs, int bits, int len,
+                                  vp9_tree_index i) {
+  do {
+    const int bit = (bits >> --len) & 1;
+    vp9_write(w, bit, probs[i >> 1]);
+    i = tree[i + bit];
+  } while (len);
+}
+
+static INLINE void vp9_write_token(vp9_writer *w, const vp9_tree_index *tree,
+                                   const vp9_prob *probs,
+                                   const struct vp9_token *token) {
+  vp9_write_tree(w, tree, probs, token->value, token->len, 0);
+}
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VP9_ENCODER_VP9_TREEWRITER_H_