Add YUV_420_BIPLANAR to gfx::BufferFormat.

ui/gl/gl_image_io_surface.mm

Index: ui/gl/gl_image_io_surface.mm
diff --git a/ui/gl/gl_image_io_surface.mm b/ui/gl/gl_image_io_surface.mm
index 2044f3775a16590370ee323eac853eb007aaf98f..847fb9aad18955229200abd1c20880156f35ae25 100644
--- a/ui/gl/gl_image_io_surface.mm
+++ b/ui/gl/gl_image_io_surface.mm
@@ -35,6 +35,7 @@ bool ValidFormat(BufferFormat format) {
   switch (format) {
     case BufferFormat::R_8:
     case BufferFormat::BGRA_8888:
+    case BufferFormat::YUV_420_BIPLANAR:
       return true;
     case BufferFormat::ATC:
     case BufferFormat::ATCIA:
@@ -55,6 +56,7 @@ bool ValidFormat(BufferFormat format) {
 GLenum TextureFormat(BufferFormat format) {
   switch (format) {
     case BufferFormat::R_8:
+    case BufferFormat::YUV_420_BIPLANAR:
       return GL_RED;
     case BufferFormat::BGRA_8888:
       return GL_RGBA;
@@ -78,6 +80,7 @@ GLenum TextureFormat(BufferFormat format) {
 GLenum DataFormat(BufferFormat format) {
   switch (format) {
     case BufferFormat::R_8:
+    case BufferFormat::YUV_420_BIPLANAR:
       return GL_RED;
     case BufferFormat::BGRA_8888:
       return GL_BGRA;
@@ -101,6 +104,7 @@ GLenum DataFormat(BufferFormat format) {
 GLenum DataType(BufferFormat format) {
   switch (format) {
     case BufferFormat::R_8:
+    case BufferFormat::YUV_420_BIPLANAR:
       return GL_UNSIGNED_BYTE;
     case BufferFormat::BGRA_8888:
       return GL_UNSIGNED_INT_8_8_8_8_REV;