cros: Ensure task manager shows correct title for lock screen webview

chrome/browser/chromeos/login/ui/web_contents_forced_title.cc

+// Copyright 2016 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/chromeos/login/ui/web_contents_forced_title.h"
+
+#include "content/public/browser/navigation_entry.h"
+#include "content/public/browser/web_contents.h"
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(chromeos::WebContentsForcedTitle);
+
+namespace chromeos {
+
+// static
+void WebContentsForcedTitle::CreateForWebContentsWithTitle(
+    content::WebContents* web_contents,
+    const base::string16& title) {
+  if (FromWebContents(web_contents))
+    return;
+
+  web_contents->UpdateTitleForEntry(nullptr, title);
+  web_contents->SetUserData(UserDataKey(),
+                            new WebContentsForcedTitle(web_contents, title));
+}
+
+WebContentsForcedTitle::WebContentsForcedTitle(
+    content::WebContents* web_contents,
+    const base::string16& title)
+    : content::WebContentsObserver(web_contents), title_(title) {}
+
+WebContentsForcedTitle::~WebContentsForcedTitle() {}
+
+void WebContentsForcedTitle::TitleWasSet(content::NavigationEntry* entry,
+                                         bool explicit_set) {
+  if (!entry || entry->GetTitle() != title_)
+    web_contents()->UpdateTitleForEntry(entry, title_);
+}
+
+}  // namespace chromeos