[sync] WebContentsObserver based sessions notifications

chrome/browser/sync/sessions/sync_sessions_router_tab_helper.cc

+// Copyright 2017 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/sync/sessions/sync_sessions_router_tab_helper.h"
+
+#include "chrome/browser/sessions/session_tab_helper.h"
+#include "chrome/browser/sync/sessions/sync_sessions_web_contents_router.h"
+#include "components/sync_sessions/synced_tab_delegate.h"
+#include "content/public/browser/navigation_entry.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/render_frame_host.h"
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(sync_sessions::SyncSessionsRouterTabHelper);
+
+namespace sync_sessions {
+
+// static
+void SyncSessionsRouterTabHelper::CreateForWebContents(
+    content::WebContents* web_contents,
+    SyncSessionsWebContentsRouter* router) {
+  DCHECK(web_contents);
+  if (!FromWebContents(web_contents)) {
+    web_contents->SetUserData(
+        UserDataKey(), new SyncSessionsRouterTabHelper(web_contents, router));
+  }
+}
+
+SyncSessionsRouterTabHelper::SyncSessionsRouterTabHelper(
+    content::WebContents* web_contents,
+    SyncSessionsWebContentsRouter* router)
+    : content::WebContentsObserver(web_contents),
+      router_(router),
+      source_tab_id_(kUnknownTabID) {}
+
+SyncSessionsRouterTabHelper::~SyncSessionsRouterTabHelper() {}
+
+void SyncSessionsRouterTabHelper::DidFinishNavigation(
+    content::NavigationHandle* navigation_handle) {
+  NotifyRouter();
+}
+
+void SyncSessionsRouterTabHelper::TitleWasSet(content::NavigationEntry* entry,
+                                              bool explicit_set) {
+  NotifyRouter();
+}
+
+void SyncSessionsRouterTabHelper::WebContentsDestroyed() {
+  NotifyRouter();
+}
+
+void SyncSessionsRouterTabHelper::DidFinishLoad(
+    content::RenderFrameHost* render_frame_host,
+    const GURL& validated_url) {
+  NotifyRouter();
+}
+
+void SyncSessionsRouterTabHelper::DidOpenRequestedURL(
+    content::WebContents* new_contents,
+    content::RenderFrameHost* source_render_frame_host,
+    const GURL& url,
+    const content::Referrer& referrer,
+    WindowOpenDisposition disposition,
+    ui::PageTransition transition,
+    bool started_from_context_menu,
+    bool renderer_initiated) {
+  SessionID::id_type source_tab_id = SessionTabHelper::IdForTab(web_contents());
+  DLOG(WARNING) << source_tab_id;

[Nicolas Zea, 2017/03/16 19:57:43]

forget to remove?

[Patrick Noland, 2017/03/17 00:20:09]

Done.

+  if (new_contents &&
+      SyncSessionsRouterTabHelper::FromWebContents(new_contents) &&
+      new_contents != web_contents() && source_tab_id != kUnknownTabID) {

[Nicolas Zea, 2017/03/16 19:57:42]

looks like kUnknownTabID already exists? Perhaps refer use that instead of -1?

[Nicolas Zea, 2017/03/16 19:57:43]

Does new_contents != web_contents() prevent source tab id from being the same as
the current tab id?

[Patrick Noland, 2017/03/16 20:23:27]

It's defined in a few places(TabNodePool as an enum, the extensions API). I'd
prefer not to rely on the extensions API just because that's where the constant
is, but maybe I could move the TabNodePool enum to SyncedTabDelegate or
SessionTabHelper? 

[Patrick Noland, 2017/03/16 20:23:27]

Yes.

+    SyncSessionsRouterTabHelper::FromWebContents(new_contents)
+        ->SetSourceTabID(source_tab_id);
+  }
+  NotifyRouter();
+}
+
+void SyncSessionsRouterTabHelper::SetSourceTabID(const SessionID::id_type id) {
+  source_tab_id_ = id;
+}
+
+void SyncSessionsRouterTabHelper::NotifyRouter() {
+  if (router_)
+    router_->NotifyTabModified(web_contents());
+}
+
+}  // namespace sync_sessions