Migrate HostZoomMap to live in StoragePartition.

chrome/browser/ui/toolbar/wrench_menu_model.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/toolbar/wrench_menu_model.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/command_line.h"
@@ skipping 265 matching lines @@
 
 WrenchMenuModel::WrenchMenuModel(ui::AcceleratorProvider* provider,
                                  Browser* browser)
     : ui::SimpleMenuModel(this),
       provider_(provider),
       browser_(browser),
       tab_strip_model_(browser_->tab_strip_model()) {
   Build();
   UpdateZoomControls();
 
+  // By asking for the HostZoomMap via the BrowserContext, we get the map
+  // associated with the default storage partition, and not the one related
+  // to any specialized storage partitions, e.g. those used by WebViewGuests.
   content_zoom_subscription_ =
       content::HostZoomMap::GetDefaultForBrowserContext(browser->profile())
           ->AddZoomLevelChangedCallback(base::Bind(
               &WrenchMenuModel::OnZoomLevelChanged, base::Unretained(this)));
 
   browser_zoom_subscription_ = ZoomEventManager::GetForBrowserContext(
       browser->profile())->AddZoomLevelChangedCallback(
           base::Bind(&WrenchMenuModel::OnZoomLevelChanged,
                      base::Unretained(this)));
 
@@ skipping 489 matching lines @@
                        ->GetZoomPercent();
   }
   zoom_label_ = l10n_util::GetStringFUTF16(
       IDS_ZOOM_PERCENT, base::IntToString16(zoom_percent));
 }
 
 void WrenchMenuModel::OnZoomLevelChanged(
     const content::HostZoomMap::ZoomLevelChange& change) {
   UpdateZoomControls();
 }