Fix Linux panels to return to minimized mode after mouse moves away.

chrome/browser/ui/panels/docked_panel_strip.cc

Index: chrome/browser/ui/panels/docked_panel_strip.cc
diff --git a/chrome/browser/ui/panels/docked_panel_strip.cc b/chrome/browser/ui/panels/docked_panel_strip.cc
index 0778d6cdee7b0618939362f68202fec57d1b22cb..1e5bb45ee9567292b2f5677d38a5afb610700b08 100644
--- a/chrome/browser/ui/panels/docked_panel_strip.cc
+++ b/chrome/browser/ui/panels/docked_panel_strip.cc
@@ -585,6 +585,9 @@ bool DockedPanelStrip::ShouldBringUpTitlebars(int mouse_x, int mouse_y) const {
 }
 
 void DockedPanelStrip::BringUpOrDownTitlebars(bool bring_up) {
+  if (are_titlebars_up_ == bring_up)
+    return;
+
   are_titlebars_up_ = bring_up;
   int task_delay_ms = 0;