Fix missing backing store in Linux.

chrome/browser/tab_contents/web_contents_view_gtk.h

Index: chrome/browser/tab_contents/web_contents_view_gtk.h
diff --git a/chrome/browser/tab_contents/web_contents_view_gtk.h b/chrome/browser/tab_contents/web_contents_view_gtk.h
index 0a562871116af7b4be93bdc6e9176f8a81914d8b..d17f39a6cbc19992b31eb74b31c14fb5c2217d15 100644
--- a/chrome/browser/tab_contents/web_contents_view_gtk.h
+++ b/chrome/browser/tab_contents/web_contents_view_gtk.h
@@ -42,6 +42,7 @@ class WebContentsViewGtk : public WebContentsView {
   virtual void SetInitialFocus();
   virtual void StoreFocus();
   virtual void RestoreFocus();
+  virtual void SetChildSize(RenderWidgetHostView* rwh_view);
 
   // Backend implementation of RenderViewHostDelegate::View.
   virtual void ShowContextMenu(const ContextMenuParams& params);
@@ -54,6 +55,7 @@ class WebContentsViewGtk : public WebContentsView {
                            const gfx::Rect& selection_rect,
                            int active_match_ordinal,
                            bool final_update);
+
  private:
   // We keep track of the timestamp of the latest mousedown event.
   static gboolean OnMouseDown(GtkWidget* widget,