Panels refactor: Support browserless panels on Linux.

chrome/browser/ui/panels/detached_panel_browsertest.cc

Index: chrome/browser/ui/panels/detached_panel_browsertest.cc
diff --git a/chrome/browser/ui/panels/detached_panel_browsertest.cc b/chrome/browser/ui/panels/detached_panel_browsertest.cc
index 901560a5ac49fb4bde7882f02b305d9b266b7dd8..2fab8c0b84adfef31ed185116d31454a9fa36741 100644
--- a/chrome/browser/ui/panels/detached_panel_browsertest.cc
+++ b/chrome/browser/ui/panels/detached_panel_browsertest.cc
@@ -9,9 +9,6 @@
 #include "chrome/browser/ui/panels/panel.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 DetachedPanelBrowserTest : public BasePanelBrowserTest {
 };
 
@@ -145,5 +142,3 @@ IN_PROC_BROWSER_TEST_F(DetachedPanelBrowserTest, ClickTitlebar) {
 
   panel_manager->CloseAll();
 }
-
-#endif // OS_WIN || OS_MACOSX