Fix missing backing store in Linux.

chrome/browser/tab_contents/web_contents_view.h

Index: chrome/browser/tab_contents/web_contents_view.h
diff --git a/chrome/browser/tab_contents/web_contents_view.h b/chrome/browser/tab_contents/web_contents_view.h
index 2efd6f2e70f857d681d9c67f8f3ceda1e2cd73b3..171d27550fb10a3f999569f3fbaba0f77ce46a53 100644
--- a/chrome/browser/tab_contents/web_contents_view.h
+++ b/chrome/browser/tab_contents/web_contents_view.h
@@ -35,7 +35,7 @@ class WaitableEvent;
 // that should be the same for all platforms.
 class WebContentsView : public RenderViewHostDelegate::View {
  public:
-  WebContentsView(WebContents* web_contents);
+  explicit WebContentsView(WebContents* web_contents);
   virtual ~WebContentsView() {}
 
   // Creates the appropriate type of WebContentsView for the current system.
@@ -121,6 +121,10 @@ class WebContentsView : public RenderViewHostDelegate::View {
   // invoked, SetInitialFocus is invoked.
   virtual void RestoreFocus() = 0;
 
+  // Sets children's size.  May involve packing them in order to get the
+  // toolkit to send them resize events.
+  virtual void SetChildSize(RenderWidgetHostView* rwh_view) = 0;
+
  protected:
   WebContentsView() {}  // Abstract interface.