Panels refactor: Support browserless panels on Linux.

chrome/browser/ui/panels/panel_drag_browsertest.cc

Index: chrome/browser/ui/panels/panel_drag_browsertest.cc
diff --git a/chrome/browser/ui/panels/panel_drag_browsertest.cc b/chrome/browser/ui/panels/panel_drag_browsertest.cc
index bf0b436f1e8026f0bb75cf421592c532a5d58195..af921a43e42646d318a4dde23adc63c53e6ba2f7 100644
--- a/chrome/browser/ui/panels/panel_drag_browsertest.cc
+++ b/chrome/browser/ui/panels/panel_drag_browsertest.cc
@@ -11,9 +11,6 @@
 #include "chrome/browser/ui/panels/panel_drag_controller.h"
 #include "chrome/browser/ui/panels/panel_manager.h"
 
-// Refactor has only been done for Win and Mac panels so far.
-#if defined(OS_WIN) || defined(OS_MACOSX)
-
 class PanelDragBrowserTest : public BasePanelBrowserTest {
  public:
   PanelDragBrowserTest() : BasePanelBrowserTest() {
@@ -1335,5 +1332,3 @@ IN_PROC_BROWSER_TEST_F(PanelDragBrowserTest, DragDetachedPanelToTop) {
 
   panel_manager->CloseAll();
 }
-
-#endif // OS_WIN || OS_MACOSX