[Extensions] Remove ExtensionFunction usage of RenderViewHost

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 5424db93d4ef0a12ae8b425dc82d1411fab5d169..00f6c6a709dbe00c91b5af0a775ac0d5fa755d95 100644
--- a/extensions/browser/guest_view/web_view/web_view_guest.cc
+++ b/extensions/browser/guest_view/web_view/web_view_guest.cc
@@ -441,6 +441,12 @@ void WebViewGuest::EmbedderFullscreenToggled(bool entered_fullscreen) {
     SetFullscreenState(false);
 }
 
+bool WebViewGuest::ZoomPropagatesFromEmbedderToGuest() const {
+  // We use the embedder's zoom iff we haven't set a zoom ourselves using
+  // e.g. webview.setZoom().
+  return !did_set_explicit_zoom_;
+}
+
 const char* WebViewGuest::GetAPINamespace() const {
   return webview::kAPINamespace;
 }
@@ -781,6 +787,7 @@ WebViewGuest::WebViewGuest(WebContents* owner_web_contents)
       is_embedder_fullscreen_(false),
       last_fullscreen_permission_was_allowed_by_embedder_(false),
       pending_zoom_factor_(0.0),
+      did_set_explicit_zoom_(false),
       weak_ptr_factory_(this) {
   web_view_guest_delegate_.reset(
       ExtensionsAPIClient::Get()->CreateWebViewGuestDelegate(this));
@@ -1155,6 +1162,7 @@ void WebViewGuest::SetName(const std::string& name) {
 }
 
 void WebViewGuest::SetZoom(double zoom_factor) {
+  did_set_explicit_zoom_ = true;
   auto* zoom_controller = ZoomController::FromWebContents(web_contents());
   DCHECK(zoom_controller);
   double zoom_level = content::ZoomFactorToZoomLevel(zoom_factor);