Simplify ZoomController by removing DefaultZoomLevel prefs machinery.

chrome/browser/ui/zoom/zoom_controller.h

Index: chrome/browser/ui/zoom/zoom_controller.h
diff --git a/chrome/browser/ui/zoom/zoom_controller.h b/chrome/browser/ui/zoom/zoom_controller.h
index f456cbd6c201647a0ce01098be9324483e3bb080..f1e6a64d0cfc1e918d1f20c2246a521ca01ffef3 100644
--- a/chrome/browser/ui/zoom/zoom_controller.h
+++ b/chrome/browser/ui/zoom/zoom_controller.h
@@ -70,6 +70,15 @@ class ZoomController : public content::WebContentsObserver,
 
   ZoomMode zoom_mode() const { return zoom_mode_; }
 
+  // Convenience method to get default zoom level. Implemented here for
+  // inlining.
+  double GetDefaultZoomLevel() const {
+    // TODO(wjmaclean) Make this refer to the webcontents-specific HostZoomMap
+    // when that becomes available.
+    return content::HostZoomMap::GetDefaultForBrowserContext(browser_context_)->
+        GetDefaultZoomLevel();
+  }
+
   // Convenience method to quickly check if the tab's at default zoom.
   bool IsAtDefaultZoom() const;
 
@@ -142,9 +151,6 @@ class ZoomController : public content::WebContentsObserver,
   // Current zoom level.
   double zoom_level_;
 
-  // Used to access the default zoom level preference.
-  DoublePrefMember default_zoom_level_;
-
   scoped_ptr<ZoomChangedEventData> event_data_;
 
   // Keeps track of the extension (if any) that initiated the last zoom change