Enable compositing opaque fixed position elements which will maintain LCD text.

content/public/common/content_features.cc

Index: content/public/common/content_features.cc
diff --git a/content/public/common/content_features.cc b/content/public/common/content_features.cc
index 3f969f5d283c970e6094cd0e80d17f46506bbb6a..8f8336986a0e93d6525a822cdc3782dc21db125c 100644
--- a/content/public/common/content_features.cc
+++ b/content/public/common/content_features.cc
@@ -24,6 +24,11 @@ const base::Feature kBrotliEncoding{"brotli-encoding",
 const base::Feature kCanvas2DImageChromium{"Canvas2DImageChromium",
                                            base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Enables the compositing of fixed position content that is opaque and can
+// preserve LCD text.
+const base::Feature kCompositeOpaqueFixedPosition{
+    "CompositeOpaqueFixedPosition", base::FEATURE_ENABLED_BY_DEFAULT};
+
 // Enables the compositing of scrolling content that supports painting the
 // background with the foreground, such that LCD text will still be enabled.
 const base::Feature kCompositeOpaqueScrollers{"CompositeOpaqueScrollers",