Declares GetHeightForWidth() for those who need it.

ash/system/user/tray_user.cc

Index: ash/system/user/tray_user.cc
diff --git a/ash/system/user/tray_user.cc b/ash/system/user/tray_user.cc
index 084ed06a2033210100b1c4ced1f8163f669175ca..0ea42c257e2cd25bd6c22487a8cb352109ae8eaf 100644
--- a/ash/system/user/tray_user.cc
+++ b/ash/system/user/tray_user.cc
@@ -171,6 +171,7 @@ class UserView : public views::View,
  private:
   // Overridden from views::View.
   virtual gfx::Size GetPreferredSize() OVERRIDE;
+  virtual int GetHeightForWidth(int width) OVERRIDE;
   virtual void Layout() OVERRIDE;
 
   // Overridden from views::ButtonListener.
@@ -442,6 +443,10 @@ gfx::Size UserView::GetPreferredSize() {
   return size;
 }
 
+int UserView::GetHeightForWidth(int width) {
+  return GetPreferredSize().height();
+}
+
 void UserView::Layout() {
   gfx::Rect contents_area(GetContentsBounds());
   if (user_card_ && logout_button_) {