<webview>: Zooming the embedder should zoom the guest by the same level.

extensions/browser/guest_view/web_view/web_view_guest.cc

Index: extensions/browser/guest_view/web_view/web_view_guest.cc
diff --git a/extensions/browser/guest_view/web_view/web_view_guest.cc b/extensions/browser/guest_view/web_view/web_view_guest.cc
index a06993356ac58a4135bcb836807562b22db54865..b68e37f2bb4f845d37874304cea97f80203cea8a 100644
--- a/extensions/browser/guest_view/web_view/web_view_guest.cc
+++ b/extensions/browser/guest_view/web_view/web_view_guest.cc
@@ -301,6 +301,9 @@ void WebViewGuest::DidAttachToEmbedder() {
   // We need to set the background opaque flag after navigation to ensure that
   // there is a RenderWidgetHostView available.
   SetAllowTransparency(allow_transparency);
+
+  if (web_view_guest_delegate_)
+    web_view_guest_delegate_->OnDidAttachToEmbedder();
 }
 
 void WebViewGuest::DidInitialize() {