[Notes] Create UserNotesTabHelper

Creates the UserNotesTabHelper class that monitors Primary Page changes
and navigations for the WebContents it's attached to. When the Primary
Page changes, a UserNotesManager is attached to it (via PageUserData).
When a navigation occurs (excluding errors, non-committed, same-document
or outside the primary main frame), the UserNoteService is notified so
it can deal with notes for the new page.

The UserNotesTabHelper is only attached if the User Notes feature is
enabled, if the session isn't off the record, and if the platform is
non-mobile.

Also adds the service method that the tab helper must use to notify
the service of navigations (left unimplemented for now).

Bug: 1303900
Change-Id: Id700fe0c920c4076a3ce76949371508857a25826
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3558830
Reviewed-by: David Bokan <bokan@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Guillaume Jenkins <gujen@google.com>
Cr-Commit-Position: refs/heads/main@{#989076}

chrome/browser/BUILD.gn

@@ -4406,6 +4406,8 @@ static_library("browser") {
       "user_notes/user_note_service_delegate_impl.h",
       "user_notes/user_note_service_factory.cc",
       "user_notes/user_note_service_factory.h",
+      "user_notes/user_notes_tab_helper.cc",
+      "user_notes/user_notes_tab_helper.h",
       "webauthn/authenticator_list_observer.h",
       "webauthn/authenticator_reference.cc",
       "webauthn/authenticator_reference.h",

chrome/browser/ui/BUILD.gn

@@ -1777,6 +1777,7 @@ static_library("ui") {
       "//components/services/app_service/public/mojom",
       "//components/ui_metrics",
       "//components/url_formatter",
+      "//components/user_notes:features",
       "//components/vector_icons",
       "//components/web_modal",
       "//components/webauthn/content/browser",

chrome/browser/ui/tab_helpers.cc

@@ -96,6 +96,7 @@
 #include "chrome/browser/ui/tab_dialogs.h"
 #include "chrome/browser/ui/tab_ui_helper.h"
 #include "chrome/browser/ui/thumbnails/thumbnail_tab_helper.h"
+#include "chrome/browser/user_notes/user_notes_tab_helper.h"
 #include "chrome/browser/vr/vr_tab_helper.h"
 #include "chrome/common/buildflags.h"
 #include "chrome/common/chrome_features.h"
@@ -134,6 +135,7 @@
 #include "components/site_engagement/content/site_engagement_service.h"
 #include "components/tracing/common/tracing_switches.h"
 #include "components/ukm/content/source_url_recorder.h"
+#include "components/user_notes/user_notes_features.h"
 #include "components/webapps/browser/installable/installable_manager.h"
 #include "content/public/browser/web_contents.h"
 #include "extensions/buildflags/buildflags.h"
@@ -530,11 +532,10 @@ void TabHelpers::AttachTabHelpers(WebContents* web_contents) {
           accuracy_tips::features::kAccuracyTipsSurveyFeature)) {
     HatsHelper::CreateForWebContents(web_contents);
   }
-#endif
-
-#if BUILDFLAG(IS_WIN) || BUILDFLAG(IS_MAC) || BUILDFLAG(IS_LINUX) || \
-    BUILDFLAG(IS_CHROMEOS)
   SharedHighlightingPromo::CreateForWebContents(web_contents);
+  if (user_notes::IsUserNotesEnabled() && !profile->IsOffTheRecord()) {
+    user_notes::UserNotesTabHelper::CreateForWebContents(web_contents);
+  }
 #endif
 
 #if BUILDFLAG(IS_WIN)

chrome/browser/user_notes/user_notes_tab_helper.cc

@@ -0,0 +1,47 @@
+// Copyright 2022 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 "chrome/browser/user_notes/user_notes_tab_helper.h"
+
+#include "chrome/browser/user_notes/user_note_service_factory.h"
+#include "components/user_notes/browser/user_note_service.h"
+#include "components/user_notes/browser/user_notes_manager.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/page.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/web_contents.h"
+
+namespace user_notes {
+
+UserNotesTabHelper::UserNotesTabHelper(content::WebContents* web_contents)
+    : WebContentsObserver(web_contents),
+      content::WebContentsUserData<UserNotesTabHelper>(*web_contents) {}
+
+UserNotesTabHelper::~UserNotesTabHelper() = default;
+
+void UserNotesTabHelper::PrimaryPageChanged(content::Page& page) {
+  if (!UserNotesManager::GetForPage(page)) {
+    UserNotesManager::CreateForPage(page, service()->GetSafeRef());
+  }
+}
+
+void UserNotesTabHelper::DidFinishNavigation(
+    content::NavigationHandle* navigation_handle) {
+  // Note: `DidFinishNavigation` is needed in addition to `PrimaryPageChanged`
+  // because of non-main frame navigations.
+  if (!navigation_handle->HasCommitted() ||
+      navigation_handle->IsSameDocument()) {
+    return;
+  }
+  service()->OnFrameNavigated(navigation_handle->GetRenderFrameHost());
+}
+
+UserNoteService* UserNotesTabHelper::service() const {
+  return UserNoteServiceFactory::GetForContext(
+      web_contents()->GetBrowserContext());
+}
+
+WEB_CONTENTS_USER_DATA_KEY_IMPL(UserNotesTabHelper);
+
+}  // namespace user_notes

chrome/browser/user_notes/user_notes_tab_helper.h

@@ -0,0 +1,51 @@
+// Copyright 2022 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 CHROME_BROWSER_USER_NOTES_USER_NOTES_TAB_HELPER_H_
+#define CHROME_BROWSER_USER_NOTES_USER_NOTES_TAB_HELPER_H_
+
+#include "content/public/browser/web_contents_observer.h"
+#include "content/public/browser/web_contents_user_data.h"
+
+namespace content {
+class NavigationHandle;
+class Page;
+class WebContents;
+}  // namespace content
+
+namespace user_notes {
+
+class UserNoteService;
+
+// An observer of WebContents that attaches User Notes page data to primary
+// pages, and notifies the User Notes service when new URLs are navigated to so
+// it can display notes.
+class UserNotesTabHelper
+    : public content::WebContentsObserver,
+      public content::WebContentsUserData<UserNotesTabHelper> {
+ public:
+  UserNotesTabHelper(const UserNotesTabHelper&) = delete;
+  UserNotesTabHelper& operator=(const UserNotesTabHelper&) = delete;
+
+  ~UserNotesTabHelper() override;
+
+ private:
+  friend class content::WebContentsUserData<UserNotesTabHelper>;
+
+  explicit UserNotesTabHelper(content::WebContents* web_contents);
+
+  UserNoteService* service() const;
+
+  // WebContentsObserver implementation.
+  void PrimaryPageChanged(content::Page& page) override;
+
+  void DidFinishNavigation(
+      content::NavigationHandle* navigation_handle) override;
+
+  WEB_CONTENTS_USER_DATA_KEY_DECL();
+};
+
+}  // namespace user_notes
+
+#endif  // CHROME_BROWSER_USER_NOTES_USER_NOTES_TAB_HELPER_H_

components/user_notes/browser/user_note_service.cc

@@ -7,6 +7,7 @@
 #include "base/notreached.h"
 #include "components/user_notes/browser/user_notes_manager.h"
 #include "components/user_notes/user_notes_features.h"
+#include "content/public/browser/render_frame_host.h"
 
 namespace user_notes {
 
@@ -20,6 +21,22 @@ base::SafeRef<UserNoteService> UserNoteService::GetSafeRef() {
   return weak_ptr_factory_.GetSafeRef();
 }
 
+void UserNoteService::OnFrameNavigated(content::RenderFrameHost* rfh) {
+  DCHECK(IsUserNotesEnabled());
+
+  // For now, Notes are only supported in the main frame.
+  if (!rfh->IsInPrimaryMainFrame()) {
+    return;
+  }
+
+  if (rfh->GetPage().GetMainDocument().IsErrorDocument()) {
+    return;
+  }
+
+  DCHECK(UserNotesManager::GetForPage(rfh->GetPage()));
+  NOTIMPLEMENTED();
+}
+
 void UserNoteService::OnNoteInstanceAddedToPage(
     const base::UnguessableToken& id,
     UserNotesManager* manager) {

components/user_notes/browser/user_note_service.h

@@ -20,6 +20,10 @@
 #include "components/user_notes/interfaces/user_notes_ui_delegate.h"
 #include "components/user_notes/model/user_note.h"
 
+namespace content {
+class RenderFrameHost;
+}  // namespace content
+
 namespace user_notes {
 
 class UserNotesManager;
@@ -35,6 +39,11 @@ class UserNoteService : public KeyedService, public UserNotesUIDelegate {
 
   base::SafeRef<UserNoteService> GetSafeRef();
 
+  // Called by the embedder when a frame navigates to a new URL. Queries the
+  // storage to find notes associated with that URL, and if there are any, kicks
+  // off the logic to display them in the page.
+  void OnFrameNavigated(content::RenderFrameHost* rfh);
+
   // Called by |UserNotesManager| objects when a |UserNoteInstance| is added to
   // the page they're attached to. Updates the model map to add a ref to the
   // given |UserNotesManager| for the note with the specified ID.

components/user_notes/browser/user_notes_manager.cc

@@ -67,4 +67,6 @@ void UserNotesManager::AddNoteInstance(std::unique_ptr<UserNoteInstance> note) {
   instance_map_.emplace(note->model().id(), std::move(note));
 }
 
+PAGE_USER_DATA_KEY_IMPL(UserNotesManager);
+
 }  // namespace user_notes