Set bookmarks bar text color to #646464 in MD mode

chrome/browser/themes/theme_properties.h

Index: chrome/browser/themes/theme_properties.h
diff --git a/chrome/browser/themes/theme_properties.h b/chrome/browser/themes/theme_properties.h
index 6b323472616c8e674f6bd2c0407de3faf5ccd830..83c719cb0beb2d235c08d4510a76d48e1819c267 100644
--- a/chrome/browser/themes/theme_properties.h
+++ b/chrome/browser/themes/theme_properties.h
@@ -107,6 +107,9 @@ class ThemeProperties {
     // The color of a background tab, as well as the new tab button.
     COLOR_BACKGROUND_TAB,
 
+    // The color of the "instructions text" in an empty bookmarks bar.
+    COLOR_BOOKMARK_BAR_INSTRUCTIONS_TEXT,
+
     // Colors used for the detached (NTP) bookmark bar.
     COLOR_DETACHED_BOOKMARK_BAR_BACKGROUND,
     COLOR_DETACHED_BOOKMARK_BAR_SEPARATOR,