Move creation and ownership of HostZoomMap to content instead of having every embedder do this.

content/browser/tab_contents/tab_contents.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 "content/browser/tab_contents/tab_contents.h"
 
 #include <cmath>
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
@@ skipping 98 matching lines @@
 // - The previous renderer is kept swapped out in RenderViewHostManager in case
 //   the user goes back.  The process only stays live if another tab is using
 //   it, but if so, the existing frame relationships will be maintained.
 
 using content::DevToolsAgentHost;
 using content::DevToolsAgentHostRegistry;
 using content::DevToolsManagerImpl;
 using content::DownloadItem;
 using content::DownloadManager;
 using content::GlobalRequestID;
+using content::HostZoomMap;
 using content::InterstitialPage;
 using content::NavigationController;
 using content::NavigationEntry;
 using content::NavigationEntryImpl;
 using content::OpenURLParams;
 using content::RenderViewHostDelegate;
 using content::RenderWidgetHostView;
 using content::RenderWidgetHostViewPort;
 using content::SiteInstance;
 using content::SSLStatus;
@@ skipping 1062 matching lines @@
 void TabContents::SetClosedByUserGesture(bool value) {
   closed_by_user_gesture_ = value;
 }
 
 bool TabContents::GetClosedByUserGesture() const {
   return closed_by_user_gesture_;
 }
 
 double TabContents::GetZoomLevel() const {
   HostZoomMapImpl* zoom_map = static_cast<HostZoomMapImpl*>(
-      GetBrowserContext()->GetHostZoomMap());
+      HostZoomMap::GetForBrowserContext(GetBrowserContext()));
   if (!zoom_map)
     return 0;
 
   double zoom_level;
   if (temporary_zoom_settings_) {
     zoom_level = zoom_map->GetTemporaryZoomLevel(
         GetRenderProcessHost()->GetID(), GetRenderViewHost()->routing_id());
   } else {
     GURL url;
     NavigationEntry* active_entry = GetController().GetActiveEntry();
@@ skipping 1255 matching lines @@
                    save_info,
                    this);
 }
 
 void TabContents::CreateViewAndSetSizeForRVH(RenderViewHost* rvh) {
   RenderWidgetHostView* rwh_view = GetView()->CreateViewForWidget(rvh);
   // Can be NULL during tests.
   if (rwh_view)
     rwh_view->SetSize(GetView()->GetContainerSize());
 }