Portals: Notify the Document when a portal is created or destroyed.

This CL also adds an API to retrieve the portal given a portal token.

Bug: 865565
Change-Id: Ie8f5e8f5aaea395811e9da3afc04fc89df48196b
Reviewed-on: https://chromium-review.googlesource.com/c/1297248Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Commit-Queue: Lucas Gadani <lfg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#604410}

third_party/blink/renderer/core/html/BUILD.gn

@@ -500,6 +500,8 @@ blink_core_sources("html") {
     "media/picture_in_picture_interstitial.h",
     "plugin_document.cc",
     "plugin_document.h",
+    "portal/document_portals.cc",
+    "portal/document_portals.h",
     "portal/html_portal_element.cc",
     "portal/html_portal_element.h",
     "rel_list.cc",

third_party/blink/renderer/core/html/portal/document_portals.cc

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "third_party/blink/renderer/core/html/portal/document_portals.h"
+
+#include "third_party/blink/renderer/core/html/portal/html_portal_element.h"
+
+namespace blink {
+
+// static
+const char DocumentPortals::kSupplementName[] = "DocumentPortals";
+
+// static
+DocumentPortals& DocumentPortals::From(Document& document) {
+  DocumentPortals* supplement =
+      Supplement<Document>::From<DocumentPortals>(document);
+  if (!supplement) {
+    supplement = new DocumentPortals(document);
+    Supplement<Document>::ProvideTo(document, supplement);
+  }
+  return *supplement;
+}
+
+DocumentPortals::DocumentPortals(Document& document)
+    : Supplement<Document>(document) {}
+
+void DocumentPortals::OnPortalInserted(HTMLPortalElement* portal) {
+  portals_.push_back(portal);
+}
+
+void DocumentPortals::OnPortalRemoved(HTMLPortalElement* portal) {
+  portals_.EraseAt(portals_.Find(portal));
+}
+
+HTMLPortalElement* DocumentPortals::GetPortal(
+    const base::UnguessableToken& token) const {
+  for (HTMLPortalElement* portal : portals_) {
+    if (portal->GetToken() == token)
+      return portal;
+  }
+
+  return nullptr;
+}
+
+void DocumentPortals::Trace(Visitor* visitor) {
+  Supplement<Document>::Trace(visitor);
+  visitor->Trace(portals_);
+}
+
+}  // namespace blink

third_party/blink/renderer/core/html/portal/document_portals.h

+// Copyright 2018 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef THIRD_PARTY_BLINK_RENDERER_CORE_HTML_PORTAL_DOCUMENT_PORTALS_H_
+#define THIRD_PARTY_BLINK_RENDERER_CORE_HTML_PORTAL_DOCUMENT_PORTALS_H_
+
+#include "third_party/blink/renderer/core/dom/document.h"
+#include "third_party/blink/renderer/platform/heap/handle.h"
+#include "third_party/blink/renderer/platform/supplementable.h"
+
+namespace blink {
+
+class HTMLPortalElement;
+
+class DocumentPortals : public GarbageCollected<DocumentPortals>,
+                        public Supplement<Document> {
+ public:
+  static const char kSupplementName[];
+  static DocumentPortals& From(Document&);
+
+  // Used to notify the document that a portal was inserted.
+  void OnPortalInserted(HTMLPortalElement* portal);
+
+  // Notifies that a portal was removed from the Document.
+  void OnPortalRemoved(HTMLPortalElement* portal);
+
+  // Retrieves the portal identified by the token.
+  HTMLPortalElement* GetPortal(const base::UnguessableToken&) const;
+
+  void Trace(Visitor*) override;
+
+ private:
+  explicit DocumentPortals(Document&);
+
+  HeapVector<Member<HTMLPortalElement>> portals_;
+};
+
+}  // namespace blink
+
+#endif  // THIRD_PARTY_BLINK_RENDERER_CORE_HTML_PORTAL_DOCUMENT_PORTALS_H_

third_party/blink/renderer/core/html/portal/html_portal_element.cc

@@ -13,6 +13,7 @@
 #include "third_party/blink/renderer/core/frame/local_frame.h"
 #include "third_party/blink/renderer/core/html/html_unknown_element.h"
 #include "third_party/blink/renderer/core/html/parser/html_parser_idioms.h"
+#include "third_party/blink/renderer/core/html/portal/document_portals.h"
 #include "third_party/blink/renderer/core/html_names.h"
 #include "third_party/blink/renderer/platform/bindings/script_state.h"
 #include "third_party/blink/renderer/platform/heap/handle.h"
@@ -85,6 +86,7 @@ HTMLPortalElement::InsertionNotificationRequest HTMLPortalElement::InsertedInto(
         [](HTMLPortalElement* portal,
            const base::UnguessableToken& portal_token) {
           portal->portal_token_ = portal_token;
+          DocumentPortals::From(portal->GetDocument()).OnPortalInserted(portal);
         },
         WrapPersistent(this)));
     Navigate();
@@ -99,6 +101,14 @@ void HTMLPortalElement::RemovedFrom(ContainerNode& node) {
   Document& document = GetDocument();
 
   if (node.IsInDocumentTree() && document.IsHTMLDocument()) {
+    // The portal creation is asynchronous, and the Document only gets notified
+    // after the element receives a callback from the browser that assigns its
+    // token, so we need to check whether that has been completed before
+    // notifying the document about the portal's removal.
+    if (!portal_token_.is_empty())
+      DocumentPortals::From(GetDocument()).OnPortalRemoved(this);
+
+    portal_token_ = base::UnguessableToken();
     portal_ptr_.reset();
   }
 }

third_party/blink/renderer/core/html/portal/html_portal_element.h

@@ -35,6 +35,8 @@ class CORE_EXPORT HTMLPortalElement : public HTMLFrameOwnerElement {
   // idl implementation.
   ScriptPromise activate(ScriptState*);
 
+  const base::UnguessableToken& GetToken() const { return portal_token_; }
+
   FrameOwnerElementType OwnerType() const override {
     return FrameOwnerElementType::kPortal;
   }