Add methods needed for overflow panels to NativePanel interface.

chrome/browser/ui/panels/panel_browser_window_cocoa.mm

Index: chrome/browser/ui/panels/panel_browser_window_cocoa.mm
diff --git a/chrome/browser/ui/panels/panel_browser_window_cocoa.mm b/chrome/browser/ui/panels/panel_browser_window_cocoa.mm
index 64a9224b6b91c83c3ede9b80d9f15a5bef249576..dd8bff2ab72f123216e155f5c481fe30ec1556cb 100644
--- a/chrome/browser/ui/panels/panel_browser_window_cocoa.mm
+++ b/chrome/browser/ui/panels/panel_browser_window_cocoa.mm
@@ -246,6 +246,15 @@ void PanelBrowserWindowCocoa::DestroyPanelBrowser() {
   [controller_ close];
 }
 
+gfx::Size PanelBrowserWindowCocoa::IconOnlySize() const {
+  // TODO(dimich): to be implemented.
+  return gfx::Size();
+}
+
+void PanelBrowserWindowCocoa::EnsurePanelFullyVisible() {
+  // TODO(dimich): to be implemented.
+}
+
 void PanelBrowserWindowCocoa::DidCloseNativeWindow() {
   DCHECK(!isClosed());
   panel_->OnNativePanelClosed();