Add R_8 GPU memory buffers format.

gpu/command_buffer/service/image_factory.cc

Index: gpu/command_buffer/service/image_factory.cc
diff --git a/gpu/command_buffer/service/image_factory.cc b/gpu/command_buffer/service/image_factory.cc
index 9a2d458abd8cf9bf3673dcc2ab43e4e69895ee41..59cae64370d74087ad22d2fd133465a86843d74f 100644
--- a/gpu/command_buffer/service/image_factory.cc
+++ b/gpu/command_buffer/service/image_factory.cc
@@ -19,6 +19,9 @@ ImageFactory::~ImageFactory() {
 gfx::GpuMemoryBuffer::Format ImageFactory::ImageFormatToGpuMemoryBufferFormat(
     unsigned internalformat) {
   switch (internalformat) {
+    case GL_LUMINANCE:
+    case GL_R8:
+      return gfx::GpuMemoryBuffer::R_8;
     case GL_RGB:
       return gfx::GpuMemoryBuffer::RGBX_8888;
     case GL_RGBA:
@@ -67,6 +70,7 @@ bool ImageFactory::IsImageFormatCompatibleWithGpuMemoryBufferFormat(
         case gfx::GpuMemoryBuffer::ETC1:
         case gfx::GpuMemoryBuffer::RGBX_8888:
           return true;
+        case gfx::GpuMemoryBuffer::R_8:
         case gfx::GpuMemoryBuffer::RGBA_8888:
         case gfx::GpuMemoryBuffer::BGRA_8888:
           return false;
@@ -75,6 +79,7 @@ bool ImageFactory::IsImageFormatCompatibleWithGpuMemoryBufferFormat(
       return false;
     case GL_RGBA:
       switch (format) {
+        case gfx::GpuMemoryBuffer::R_8:
         case gfx::GpuMemoryBuffer::RGBX_8888:
           return false;
         case gfx::GpuMemoryBuffer::ATC:
@@ -88,6 +93,9 @@ bool ImageFactory::IsImageFormatCompatibleWithGpuMemoryBufferFormat(
       }
       NOTREACHED();
       return false;
+    case GL_LUMINANCE:
+    case GL_R8:
+      return format == gfx::GpuMemoryBuffer::R_8;
     default:
       NOTREACHED();
       return false;
@@ -110,6 +118,7 @@ bool ImageFactory::IsGpuMemoryBufferFormatSupported(
       return capabilities.texture_format_dxt5;
     case gfx::GpuMemoryBuffer::ETC1:
       return capabilities.texture_format_etc1;
+    case gfx::GpuMemoryBuffer::R_8:
     case gfx::GpuMemoryBuffer::RGBA_8888:
     case gfx::GpuMemoryBuffer::RGBX_8888:
       return true;
@@ -132,6 +141,7 @@ bool ImageFactory::IsImageSizeValidForGpuMemoryBufferFormat(
       // Compressed images must have a width and height that's evenly divisible
       // by the block size.
       return size.width() % 4 == 0 && size.height() % 4 == 0;
+    case gfx::GpuMemoryBuffer::R_8:
     case gfx::GpuMemoryBuffer::RGBA_8888:
     case gfx::GpuMemoryBuffer::BGRA_8888:
     case gfx::GpuMemoryBuffer::RGBX_8888: