libvpx: Pull from upstream

source/libvpx/vp9/common/vp9_systemdependent.h

Index: source/libvpx/vp9/common/vp9_systemdependent.h
===================================================================
--- source/libvpx/vp9/common/vp9_systemdependent.h	(revision 177019)
+++ source/libvpx/vp9/common/vp9_systemdependent.h	(working copy)
@@ -7,10 +7,15 @@
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
+
 #ifndef VP9_COMMON_VP9_SYSTEMDEPENDENT_H_
 #define VP9_COMMON_VP9_SYSTEMDEPENDENT_H_
 
-#include "vpx_ports/config.h"
+#ifdef _MSC_VER
+#include <math.h>
+#endif
+
+#include "./vpx_config.h"
 #if ARCH_X86 || ARCH_X86_64
 void vpx_reset_mmx_state(void);
 #define vp9_clear_system_state() vpx_reset_mmx_state()
@@ -18,6 +23,17 @@
 #define vp9_clear_system_state()
 #endif
 
+#ifdef _MSC_VER
+// round is not defined in MSVC
+static int round(double x) {
+  if (x < 0)
+    return (int)ceil(x - 0.5);
+  else
+    return (int)floor(x + 0.5);
+}
+#endif
+
 struct VP9Common;
 void vp9_machine_specific_config(struct VP9Common *);
-#endif
+
+#endif  // VP9_COMMON_VP9_SYSTEMDEPENDENT_H_