Switch ZoomTabHelper to use WebContentsUserData.

chrome/browser/ui/browser.cc

Index: chrome/browser/ui/browser.cc
diff --git a/chrome/browser/ui/browser.cc b/chrome/browser/ui/browser.cc
index 5523076186fdb4e67bbc6bdde4c033ae167d9873..fd3daa21fa27a25d6f2533ab0cd3d2ca7138e352 100644
--- a/chrome/browser/ui/browser.cc
+++ b/chrome/browser/ui/browser.cc
@@ -1759,8 +1759,9 @@ void Browser::URLStarredChanged(content::WebContents* web_contents,
 ///////////////////////////////////////////////////////////////////////////////
 // Browser, ZoomObserver implementation:
 
-void Browser::OnZoomChanged(TabContents* source, bool can_show_bubble) {
-  if (source == chrome::GetActiveTabContents(this)) {
+void Browser::OnZoomChanged(content::WebContents* source,
+                            bool can_show_bubble) {
+  if (source == chrome::GetActiveWebContents(this)) {
     // Only show the zoom bubble for zoom changes in the active window.
     window_->ZoomChangedForActiveTab(can_show_bubble && window_->IsActive());
   }