Make options zoom isolated, match embedder zoom on navigation.

extensions/browser/guest_view/extension_options/extension_options_guest.cc

Index: extensions/browser/guest_view/extension_options/extension_options_guest.cc
diff --git a/extensions/browser/guest_view/extension_options/extension_options_guest.cc b/extensions/browser/guest_view/extension_options/extension_options_guest.cc
index 6041be6a891bafd3a235e627ef83dd94ead6cf8a..5ec8cb4492b4c0da7cfc274f51e0e4a28ae11f05 100644
--- a/extensions/browser/guest_view/extension_options/extension_options_guest.cc
+++ b/extensions/browser/guest_view/extension_options/extension_options_guest.cc
@@ -223,9 +223,17 @@ bool ExtensionOptionsGuest::ShouldCreateWebContents(
 void ExtensionOptionsGuest::DidNavigateMainFrame(
     const content::LoadCommittedDetails& details,
     const content::FrameNavigateParams& params) {
-  if (attached() && (params.url.GetOrigin() != options_page_.GetOrigin())) {
-    bad_message::ReceivedBadMessage(web_contents()->GetRenderProcessHost(),
-                                    bad_message::EOG_BAD_ORIGIN);
+  if (attached()) {
+    auto guest_zoom_controller =
+        ui_zoom::ZoomController::FromWebContents(web_contents());
+    guest_zoom_controller->SetZoomMode(
+        ui_zoom::ZoomController::ZOOM_MODE_ISOLATED);
+    SetGuestZoomLevelToMatchEmbedder();
+
+    if (params.url.GetOrigin() != options_page_.GetOrigin()) {
+      bad_message::ReceivedBadMessage(web_contents()->GetRenderProcessHost(),
+                                      bad_message::EOG_BAD_ORIGIN);
+    }
   }
 }