Clean up TCW, make it solely a hub for 1:1 observer/helper objects.

chrome/browser/ui/webui/print_preview_ui.cc

Index: chrome/browser/ui/webui/print_preview_ui.cc
diff --git a/chrome/browser/ui/webui/print_preview_ui.cc b/chrome/browser/ui/webui/print_preview_ui.cc
index dd4a725d05fd7ed531cfaa99aa8f81b61a717687..43b230b2fa17529db26f351af358eaeb07ea09b7 100644
--- a/chrome/browser/ui/webui/print_preview_ui.cc
+++ b/chrome/browser/ui/webui/print_preview_ui.cc
@@ -126,10 +126,10 @@ void PrintPreviewUI::SetInitiatorTabURLAndTitle(
 void PrintPreviewUI::SetSourceIsModifiable(
     TabContentsWrapper* print_preview_tab,
     bool source_is_modifiable) {
-  if (!print_preview_tab || !print_preview_tab->web_ui())
+  if (!print_preview_tab || !print_preview_tab->tab_contents()->web_ui())
     return;
   PrintPreviewUI* print_preview_ui =
-      static_cast<PrintPreviewUI*>(print_preview_tab->web_ui());
+      static_cast<PrintPreviewUI*>(print_preview_tab->tab_contents()->web_ui());
   print_preview_ui->source_is_modifiable_ = source_is_modifiable;
 }