Add R_8 GPU memory buffers format.

gpu/command_buffer/tests/gl_manager.cc

Index: gpu/command_buffer/tests/gl_manager.cc
diff --git a/gpu/command_buffer/tests/gl_manager.cc b/gpu/command_buffer/tests/gl_manager.cc
index 3a3d7e9efdca6a097c5c8330fceae42b7a8392ce..2b6d06dbc22634d829354867406d26dca2de0dcd 100644
--- a/gpu/command_buffer/tests/gl_manager.cc
+++ b/gpu/command_buffer/tests/gl_manager.cc
@@ -46,6 +46,7 @@ size_t NumberOfPlanesForGpuMemoryBufferFormat(
     case gfx::GpuMemoryBuffer::Format::DXT1:
     case gfx::GpuMemoryBuffer::Format::DXT5:
     case gfx::GpuMemoryBuffer::Format::ETC1:
+    case gfx::GpuMemoryBuffer::Format::R_8:
     case gfx::GpuMemoryBuffer::Format::RGBA_8888:
     case gfx::GpuMemoryBuffer::Format::RGBX_8888:
     case gfx::GpuMemoryBuffer::Format::BGRA_8888:
@@ -64,6 +65,7 @@ size_t SubsamplingFactor(gfx::GpuMemoryBuffer::Format format, int plane) {
     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::RGBX_8888:
     case gfx::GpuMemoryBuffer::BGRA_8888:
@@ -92,6 +94,8 @@ size_t StrideInBytes(size_t width,
       DCHECK_EQ(plane, 0);
       DCHECK_EQ(width % 2, 0U);
       return width / 2;
+    case gfx::GpuMemoryBuffer::R_8:
+      return (width + 3) & ~0x3;
     case gfx::GpuMemoryBuffer::RGBA_8888:
     case gfx::GpuMemoryBuffer::BGRA_8888:
       DCHECK_EQ(plane, 0);