Add command buffer support for EXT_sRGB_write_control

gpu/command_buffer/service/context_state_autogen.h

Index: gpu/command_buffer/service/context_state_autogen.h
diff --git a/gpu/command_buffer/service/context_state_autogen.h b/gpu/command_buffer/service/context_state_autogen.h
index c0da2cd1d8bdf3a0f0fca5f05f01921c75ea1c02..38fae6e48d59870fe2ad1ac32fe3dcad311cee9f 100644
--- a/gpu/command_buffer/service/context_state_autogen.h
+++ b/gpu/command_buffer/service/context_state_autogen.h
@@ -22,6 +22,8 @@ struct EnableFlags {
   bool cached_depth_test;
   bool dither;
   bool cached_dither;
+  bool framebuffer_srgb_ext;
+  bool cached_framebuffer_srgb_ext;
   bool polygon_offset_fill;
   bool cached_polygon_offset_fill;
   bool sample_alpha_to_coverage;
@@ -143,6 +145,12 @@ inline void SetDeviceCapabilityState(GLenum cap, bool enable) {
         return;
       enable_flags.cached_dither = enable;
       break;
+    case GL_FRAMEBUFFER_SRGB_EXT:
+      if (enable_flags.cached_framebuffer_srgb_ext == enable &&
+          !ignore_cached_state)
+        return;
+      enable_flags.cached_framebuffer_srgb_ext = enable;
+      break;
     case GL_POLYGON_OFFSET_FILL:
       if (enable_flags.cached_polygon_offset_fill == enable &&
           !ignore_cached_state)