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

chrome/browser/ssl/ssl_blocking_page.cc

Index: chrome/browser/ssl/ssl_blocking_page.cc
diff --git a/chrome/browser/ssl/ssl_blocking_page.cc b/chrome/browser/ssl/ssl_blocking_page.cc
index f9aa36ae16bf1acb50a0e50826c794f1437161ba..7664cf5da1c58241b3931e2a24a5df12df688993 100644
--- a/chrome/browser/ssl/ssl_blocking_page.cc
+++ b/chrome/browser/ssl/ssl_blocking_page.cc
@@ -29,6 +29,7 @@
 #include "chrome/grit/generated_resources.h"
 #include "components/google/core/browser/google_util.h"
 #include "content/public/browser/cert_store.h"
+#include "content/public/browser/host_zoom_map.h"
 #include "content/public/browser/interstitial_page.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
@@ -37,6 +38,7 @@
 #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/renderer_preferences.h"
 #include "content/public/common/ssl_status.h"
 #include "grit/browser_resources.h"
 #include "net/base/hash_value.h"
@@ -585,6 +587,10 @@ void SSLBlockingPage::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 SSLBlockingPage::OnProceed() {