Add R_8 GPU memory buffers format.

ui/gl/gl_image_linux_dma_buffer.cc

Index: ui/gl/gl_image_linux_dma_buffer.cc
diff --git a/ui/gl/gl_image_linux_dma_buffer.cc b/ui/gl/gl_image_linux_dma_buffer.cc
index 04ad06bd438433b270c60b804509a088d08e0a44..0ce27a6eedac12a19a4a8bd66c26f2cc4143df75 100644
--- a/ui/gl/gl_image_linux_dma_buffer.cc
+++ b/ui/gl/gl_image_linux_dma_buffer.cc
@@ -37,6 +37,7 @@ bool ValidFormat(unsigned internalformat, gfx::GpuMemoryBuffer::Format format) {
         case gfx::GpuMemoryBuffer::DXT1:
         case gfx::GpuMemoryBuffer::DXT5:
         case gfx::GpuMemoryBuffer::ETC1:
+        case gfx::GpuMemoryBuffer::R_8:
         case gfx::GpuMemoryBuffer::RGBA_8888:
         case gfx::GpuMemoryBuffer::BGRA_8888:
           return false;
@@ -52,12 +53,15 @@ bool ValidFormat(unsigned internalformat, gfx::GpuMemoryBuffer::Format format) {
         case gfx::GpuMemoryBuffer::DXT1:
         case gfx::GpuMemoryBuffer::DXT5:
         case gfx::GpuMemoryBuffer::ETC1:
+        case gfx::GpuMemoryBuffer::R_8:
         case gfx::GpuMemoryBuffer::RGBX_8888:
         case gfx::GpuMemoryBuffer::RGBA_8888:
           return false;
       }
       NOTREACHED();
       return false;
+    case GL_R8:
+      return false;
     default:
       return false;
   }
@@ -74,6 +78,7 @@ EGLint FourCC(gfx::GpuMemoryBuffer::Format format) {
     case gfx::GpuMemoryBuffer::DXT1:
     case gfx::GpuMemoryBuffer::DXT5:
     case gfx::GpuMemoryBuffer::ETC1:
+    case gfx::GpuMemoryBuffer::R_8:
     case gfx::GpuMemoryBuffer::RGBA_8888:
       NOTREACHED();
       return 0;