Pull shell window stuff out of ExtensionHost and put in ShellWindow

chrome/browser/ui/gtk/extensions/shell_window_gtk.h

Index: chrome/browser/ui/gtk/extensions/shell_window_gtk.h
diff --git a/chrome/browser/ui/gtk/extensions/shell_window_gtk.h b/chrome/browser/ui/gtk/extensions/shell_window_gtk.h
index 256f3c385aaa412700ca0eebba552f20e65c3669..983195778ae1e050596008dda630be4bc8b29e67 100644
--- a/chrome/browser/ui/gtk/extensions/shell_window_gtk.h
+++ b/chrome/browser/ui/gtk/extensions/shell_window_gtk.h
@@ -14,13 +14,13 @@
 #include "ui/base/x/active_window_watcher_x_observer.h"
 #include "ui/gfx/rect.h"
 
-class ExtensionHost;
+class PlatformAppHost;
 
 class ShellWindowGtk : public ShellWindow,
                        public ExtensionViewGtk::Container,
                        public ui::ActiveWindowWatcherXObserver {
  public:
-  explicit ShellWindowGtk(ExtensionHost* host);
+  explicit ShellWindowGtk(PlatformAppHost* host);
 
   // BaseWindow implementation.
   virtual bool IsActive() const OVERRIDE;