Linux: work around browser windows that get stuck maximized by the WM.

chrome/browser/gtk/browser_window_gtk.h

Index: chrome/browser/gtk/browser_window_gtk.h
===================================================================
--- chrome/browser/gtk/browser_window_gtk.h	(revision 27114)
+++ chrome/browser/gtk/browser_window_gtk.h	(working copy)
@@ -143,6 +143,10 @@
   void OnDebouncedBoundsChanged();
   void OnStateChanged(GdkWindowState state, GdkWindowState changed_mask);
 
+  // Request the underlying window to unmaximize.  Also tries to work around
+  // a window manager "feature" that can prevent this in some edge cases.
+  void UnMaximize();
+
   // Returns false if we're not ready to close yet.  E.g., a tab may have an
   // onbeforeunload handler that prevents us from closing.
   bool CanClose() const;