Linux Aura: Use system title bar is now set by preference, not flag.

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 73bd205772468a26755abe3f092c8fad26e4729c..8e830649a30acdb77d3aed62a2261c791b36ef86 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -14365,15 +14365,6 @@ Do you accept?
       Enable Web MIDI API experimental support.
     </message>
 
-    <message name="IDS_FLAGS_USE_SYSTEM_TITLE_BAR"
-             desc="Name of about:flag option to use the host operating system's title bar and window borders.">
-      Use system title bar and borders
-    </message>
-    <message name="IDS_FLAGS_USE_SYSTEM_TITLE_BAR_DESCRIPTION"
-             desc="Description of about:flag option to turn on the host operating system's title bar and window borders.">
-      Use the host operating system's window title bar and borders, instead of custom window dressing.
-    </message>
-
     <!-- Toast experiment. -->
     <message name="IDS_TRY_TOAST_SET_DEFAULT" desc="Text of the checkbox to make chrome the default browser">
       Make it my default browser