Revert 255617, due to it not tracking use of the link doctor page properly.

chrome/browser/ui/alternate_error_tab_observer.cc

+// Copyright (c) 2012 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/ui/alternate_error_tab_observer.h"
+
+#include "base/prefs/pref_service.h"
+#include "chrome/browser/chrome_notification_types.h"
+#include "chrome/browser/google/google_util.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/pref_names.h"
+#include "chrome/common/render_messages.h"
+#include "components/user_prefs/pref_registry_syncable.h"
+#include "content/public/browser/notification_service.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/web_contents.h"
+
+using content::RenderFrameHost;
+using content::RenderViewHost;
+using content::WebContents;
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(AlternateErrorPageTabObserver);
+
+AlternateErrorPageTabObserver::AlternateErrorPageTabObserver(
+    WebContents* web_contents)
+    : content::WebContentsObserver(web_contents),
+      profile_(Profile::FromBrowserContext(web_contents->GetBrowserContext())) {
+  PrefService* prefs = profile_->GetPrefs();
+  if (prefs) {
+    pref_change_registrar_.Init(prefs);
+    pref_change_registrar_.Add(
+        prefs::kAlternateErrorPagesEnabled,
+        base::Bind(&AlternateErrorPageTabObserver::
+                       OnAlternateErrorPagesEnabledChanged,
+                   base::Unretained(this)));
+  }
+
+  registrar_.Add(this, chrome::NOTIFICATION_GOOGLE_URL_UPDATED,
+                 content::Source<Profile>(profile_->GetOriginalProfile()));
+}
+
+AlternateErrorPageTabObserver::~AlternateErrorPageTabObserver() {
+}
+
+// static
+void AlternateErrorPageTabObserver::RegisterProfilePrefs(
+    user_prefs::PrefRegistrySyncable* prefs) {
+  prefs->RegisterBooleanPref(prefs::kAlternateErrorPagesEnabled,
+                             true,
+                             user_prefs::PrefRegistrySyncable::SYNCABLE_PREF);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// WebContentsObserver overrides
+
+void AlternateErrorPageTabObserver::RenderViewCreated(
+    RenderViewHost* render_view_host) {
+  UpdateAlternateErrorPageURL(render_view_host);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// content::NotificationObserver overrides
+
+void AlternateErrorPageTabObserver::Observe(
+    int type,
+    const content::NotificationSource& source,
+    const content::NotificationDetails& details) {
+  DCHECK_EQ(chrome::NOTIFICATION_GOOGLE_URL_UPDATED, type);
+  UpdateAlternateErrorPageURL(web_contents()->GetRenderViewHost());
+}
+
+////////////////////////////////////////////////////////////////////////////////
+// Internal helpers
+
+GURL AlternateErrorPageTabObserver::GetAlternateErrorPageURL() const {
+  GURL url;
+  // Disable alternate error pages when in Incognito mode.
+  if (profile_->IsOffTheRecord())
+    return url;
+
+  if (profile_->GetPrefs()->GetBoolean(prefs::kAlternateErrorPagesEnabled)) {
+    url = google_util::LinkDoctorBaseURL();
+    if (!url.is_valid())
+      return url;
+    url = google_util::AppendGoogleLocaleParam(url);
+    url = google_util::AppendGoogleTLDParam(profile_, url);
+  }
+  return url;
+}
+
+void AlternateErrorPageTabObserver::OnAlternateErrorPagesEnabledChanged() {
+  UpdateAlternateErrorPageURL(web_contents()->GetRenderViewHost());
+}
+
+void AlternateErrorPageTabObserver::UpdateAlternateErrorPageURL(
+    RenderViewHost* rvh) {
+  RenderFrameHost* rfh = rvh->GetMainFrame();
+  rfh->Send(new ChromeViewMsg_SetAltErrorPageURL(
+                rfh->GetRoutingID(), GetAlternateErrorPageURL()));
+}