Accelerate the lighten blendmode if GL_EXT_blend_minmax is enabled.

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 9bf037f0060ee86dc4e13a78fdfa0040566bdfeb..052d56ab480daeb4518757b3604333e29f29c2d6 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -2746,6 +2746,7 @@ Capabilities GLES2DecoderImpl::GetCapabilities() {
   caps.post_sub_buffer = supports_post_sub_buffer_;
   caps.image = true;
 
+  caps.blend_minmax = feature_info_->feature_flags().ext_blend_minmax;
   return caps;
 }