libvpx: Pull from upstream

source/libvpx/vp9/vp9_iface_common.h

Index: source/libvpx/vp9/vp9_iface_common.h
===================================================================
--- source/libvpx/vp9/vp9_iface_common.h	(revision 247498)
+++ source/libvpx/vp9/vp9_iface_common.h	(working copy)
@@ -29,7 +29,7 @@
     img->fmt = VPX_IMG_FMT_I420;
   }
   img->w = yv12->y_stride;
-  img->h = ALIGN_POWER_OF_TWO(yv12->y_height + 2 * VP9BORDERINPIXELS, 3);
+  img->h = ALIGN_POWER_OF_TWO(yv12->y_height + 2 * VP9_ENC_BORDER_IN_PIXELS, 3);
   img->d_w = yv12->y_crop_width;
   img->d_h = yv12->y_crop_height;
   img->x_chroma_shift = yv12->uv_width < yv12->y_width;
@@ -75,7 +75,7 @@
 
   yv12->border  = (img->stride[VPX_PLANE_Y] - img->w) / 2;
 #if CONFIG_ALPHA
-  // For development purposes, force alpha to hold the same data a Y for now.
+  // For development purposes, force alpha to hold the same data as Y for now.
   yv12->alpha_buffer = yv12->y_buffer;
   yv12->alpha_width = yv12->y_width;
   yv12->alpha_height = yv12->y_height;