Introduce ChromeZoomLevelPref, make zoom level prefs independent of profile prefs.

chrome/browser/chromeos/offline/offline_load_page.cc

Index: chrome/browser/chromeos/offline/offline_load_page.cc
diff --git a/chrome/browser/chromeos/offline/offline_load_page.cc b/chrome/browser/chromeos/offline/offline_load_page.cc
index 557eff9118b5dabf1f5d6a9b53184c0e4efb95c6..4fa7bcc32eb356c72a5600bb13d474a3c01b6e22 100644
--- a/chrome/browser/chromeos/offline/offline_load_page.cc
+++ b/chrome/browser/chromeos/offline/offline_load_page.cc
@@ -26,9 +26,11 @@
 #include "chrome/common/url_constants.h"
 #include "chrome/grit/browser_resources.h"
 #include "content/public/browser/browser_thread.h"
+#include "content/public/browser/host_zoom_map.h"
 #include "content/public/browser/interstitial_page.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/web_contents.h"
+#include "content/public/common/renderer_preferences.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system.h"
 #include "extensions/common/extension.h"
@@ -104,6 +106,10 @@ void OfflineLoadPage::OverrideRendererPrefs(
   Profile* profile = Profile::FromBrowserContext(
       web_contents_->GetBrowserContext());
   renderer_preferences_util::UpdateFromSystemSettings(prefs, profile);
+  // TODO(wjmaclean): Convert this to use the HostZoomMap for the WebContents
+  // when HostZoomMap moves to StoragePartition.
+  prefs->default_zoom_level = content::HostZoomMap::GetDefaultForBrowserContext(
+                                  profile)->GetDefaultZoomLevel();
 }
 
 void OfflineLoadPage::OnProceed() {