Make sure WebContents passed to chrome_page_zoom::Zoom() have a ZoomController.

chrome/browser/ui/zoom/zoom_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/zoom/zoom_controller.h"
 
 #include "base/prefs/pref_service.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/browser_finder.h"
 #include "chrome/browser/ui/zoom/zoom_event_manager.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/host_zoom_map.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/page_zoom.h"
 #include "extensions/common/extension.h"
 #include "grit/theme_resources.h"
 #include "net/base/net_util.h"
 
 DEFINE_WEB_CONTENTS_USER_DATA_KEY(ZoomController);
 
 ZoomController::ZoomController(content::WebContents* web_contents)
     : content::WebContentsObserver(web_contents),
+      can_show_bubble_(true),
       zoom_mode_(ZOOM_MODE_DEFAULT),
       zoom_level_(1.0),
       browser_context_(web_contents->GetBrowserContext()) {
   Profile* profile =
       Profile::FromBrowserContext(web_contents->GetBrowserContext());
   default_zoom_level_.Init(
       prefs::kDefaultZoomLevel,
       profile->GetPrefs(),
       base::Bind(
           &ZoomController::UpdateState, base::Unretained(this), std::string()));
@@ skipping 227 matching lines @@
     // Use the navigation entry's URL instead of the WebContents' so virtual
     // URLs work (e.g. chrome://settings). http://crbug.com/153950
     content::NavigationEntry* entry =
         web_contents()->GetController().GetLastCommittedEntry();
     if (!entry ||
         host != net::GetHostOrSpecFromURL(entry->GetURL())) {
       return;
     }
   }
 
-  // The zoom bubble can be shown for all zoom changes where the host is
-  // not empty.
-  bool can_show_bubble = !host.empty();
+  // The zoom bubble should not be shown for zoom changes where the host is
+  // empty.
+  bool can_show_bubble = can_show_bubble_ && !host.empty();
 
   if (event_data_) {
     // For state changes initiated within the ZoomController, information about
     // the change should be sent.
     ZoomChangedEventData zoom_change_data = *event_data_;
     event_data_.reset();
     zoom_change_data.can_show_bubble = can_show_bubble;
     FOR_EACH_OBSERVER(
         ZoomObserver, observers_, OnZoomChanged(zoom_change_data));
   } else {
     // TODO(wjmaclean) Should we consider having HostZoomMap send both old and
     // new zoom levels here?
     double zoom_level = GetZoomLevel();
     ZoomChangedEventData zoom_change_data(
         web_contents(), zoom_level, zoom_level, zoom_mode_, can_show_bubble);
     FOR_EACH_OBSERVER(
         ZoomObserver, observers_, OnZoomChanged(zoom_change_data));
   }
 }