Make <webview> use out-of-process iframe architecture.

extensions/renderer/guest_view/extensions_guest_view_container.cc

Index: extensions/renderer/guest_view/extensions_guest_view_container.cc
diff --git a/extensions/renderer/guest_view/extensions_guest_view_container.cc b/extensions/renderer/guest_view/extensions_guest_view_container.cc
index 96650d84ff934b36606217dda45b2351076330b8..3fa9882a9cd013d6cd689f5677108529eb883450 100644
--- a/extensions/renderer/guest_view/extensions_guest_view_container.cc
+++ b/extensions/renderer/guest_view/extensions_guest_view_container.cc
@@ -13,7 +13,6 @@ namespace extensions {
 ExtensionsGuestViewContainer::ExtensionsGuestViewContainer(
     content::RenderFrame* render_frame)
     : GuestViewContainer(render_frame),
-      destruction_isolate_(nullptr),
       element_resize_isolate_(nullptr),
       weak_ptr_factory_(this) {
 }
@@ -22,33 +21,6 @@ ExtensionsGuestViewContainer::~ExtensionsGuestViewContainer() {
 }
 
 void ExtensionsGuestViewContainer::OnDestroy(bool embedder_frame_destroyed) {
-  // Do not attempt to run |destruction_callback_| if the embedder frame was
-  // destroyed. Trying to invoke callback on RenderFrame destruction results in
-  // assertion failure when calling WebScopedMicrotaskSuppression.
-  if (embedder_frame_destroyed)
-    return;
-
-  // Call the destruction callback, if one is registered.
-  if (!destruction_callback_.IsEmpty()) {
-    v8::HandleScope handle_scope(destruction_isolate_);
-    v8::Local<v8::Function> callback = v8::Local<v8::Function>::New(
-        destruction_isolate_, destruction_callback_);
-    v8::Local<v8::Context> context = callback->CreationContext();
-    if (context.IsEmpty())
-      return;
-
-    v8::Context::Scope context_scope(context);
-    blink::WebScopedMicrotaskSuppression suppression;
-
-    callback->Call(context->Global(), 0 /* argc */, nullptr);
-  }
-}
-
-void ExtensionsGuestViewContainer::RegisterDestructionCallback(
-    v8::Local<v8::Function> callback,
-    v8::Isolate* isolate) {
-  destruction_callback_.Reset(isolate, callback);
-  destruction_isolate_ = isolate;
 }
 
 void ExtensionsGuestViewContainer::RegisterElementResizeCallback(