Add chrome://ntp-tiles-internals/

Implement it for Android, Desktop, and iOS.

This largely supersedes chrome://popular-sites-internals/. Relative to
that, it lacks a way to see the cached JSON and the status of a manual
fetch.

BUG=655622

Review-Url: https://codereview.chromium.org/2557103004
Cr-Commit-Position: refs/heads/master@{#438205}

chrome/browser/ui/BUILD.gn

@@ -376,6 +376,8 @@ split_static_library("ui") {
     "webui/net_internals/net_internals_ui.h",
     "webui/ntp/ntp_user_data_logger.cc",
     "webui/ntp/ntp_user_data_logger.h",
+    "webui/ntp_tiles_internals_ui.cc",
+    "webui/ntp_tiles_internals_ui.h",
     "webui/omnibox/omnibox_page_handler.cc",
     "webui/omnibox/omnibox_page_handler.h",
     "webui/omnibox/omnibox_ui.cc",
@@ -502,6 +504,7 @@ split_static_library("ui") {
     "//components/google/core/browser",
     "//components/guest_view/browser",
     "//components/history/content/browser",
+    "//components/image_fetcher",
     "//components/infobars/core",
     "//components/invalidation/impl",
     "//components/keyed_service/content",

chrome/browser/ui/webui/chrome_web_ui_controller_factory.cc

@@ -40,6 +40,7 @@
 #include "chrome/browser/ui/webui/log_web_ui_url.h"
 #include "chrome/browser/ui/webui/net_export_ui.h"
 #include "chrome/browser/ui/webui/net_internals/net_internals_ui.h"
+#include "chrome/browser/ui/webui/ntp_tiles_internals_ui.h"
 #include "chrome/browser/ui/webui/omnibox/omnibox_ui.h"
 #include "chrome/browser/ui/webui/options/options_ui.h"
 #include "chrome/browser/ui/webui/password_manager_internals/password_manager_internals_ui.h"
@@ -352,6 +353,8 @@ WebUIFactoryFunction GetWebUIFactoryFunction(WebUI* web_ui,
     return &NewWebUI<NetExportUI>;
   if (url.host_piece() == chrome::kChromeUINetInternalsHost)
     return &NewWebUI<NetInternalsUI>;
+  if (url.host_piece() == chrome::kChromeUINTPTilesInternalsHost)
+    return &NewWebUI<NTPTilesInternalsUI>;
   if (url.host_piece() == chrome::kChromeUIOmniboxHost)
     return &NewWebUI<OmniboxUI>;
   if (url.host_piece() == chrome::kChromeUIPasswordManagerInternalsHost)

chrome/browser/ui/webui/ntp_tiles_internals_ui.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/ui/webui/ntp_tiles_internals_ui.h"
+
+#include "base/bind.h"
+#include "base/memory/ptr_util.h"
+#include "chrome/browser/favicon/favicon_service_factory.h"
+#include "chrome/browser/history/top_sites_factory.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/search/suggestions/image_decoder_impl.h"
+#include "chrome/browser/search/suggestions/suggestions_service_factory.h"
+#include "chrome/browser/search_engines/template_url_service_factory.h"
+#include "chrome/common/url_constants.h"
+#include "components/grit/components_resources.h"
+#include "components/history/core/browser/top_sites.h"
+#include "components/image_fetcher/image_fetcher_impl.h"
+#include "components/ntp_tiles/field_trial.h"
+#include "components/ntp_tiles/icon_cacher.h"
+#include "components/ntp_tiles/most_visited_sites.h"
+#include "components/ntp_tiles/webui/ntp_tiles_internals_message_handler.h"
+#include "components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/web_ui.h"
+#include "content/public/browser/web_ui_data_source.h"
+#include "content/public/browser/web_ui_message_handler.h"
+
+#if defined(OS_ANDROID)
+#include "chrome/browser/android/ntp/popular_sites.h"
+#endif
+
+namespace {
+
+// The implementation for the chrome://ntp-tiles-internals page.
+class ChromeNTPTilesInternalsMessageHandlerClient
+    : public content::WebUIMessageHandler,
+      public ntp_tiles::NTPTilesInternalsMessageHandlerClient {
+ public:
+  ChromeNTPTilesInternalsMessageHandlerClient() {}
+
+ private:
+  // content::WebUIMessageHandler:
+  void RegisterMessages() override;
+
+  // ntp_tiles::NTPTilesInternalsMessageHandlerClient
+  bool DoesSourceExist(ntp_tiles::NTPTileSource source) override;
+  std::unique_ptr<ntp_tiles::MostVisitedSites> MakeMostVisitedSites() override;
+  std::unique_ptr<ntp_tiles::PopularSites> MakePopularSites() override;
+  PrefService* GetPrefs() override;
+  void RegisterMessageCallback(
+      const std::string& message,
+      const base::Callback<void(const base::ListValue*)>& callback) override;
+  void CallJavascriptFunctionVector(
+      const std::string& name,
+      const std::vector<const base::Value*>& values) override;
+
+  ntp_tiles::NTPTilesInternalsMessageHandler handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeNTPTilesInternalsMessageHandlerClient);
+};
+
+void ChromeNTPTilesInternalsMessageHandlerClient::RegisterMessages() {
+  handler_.RegisterMessages(this);
+}
+
+bool ChromeNTPTilesInternalsMessageHandlerClient::DoesSourceExist(
+    ntp_tiles::NTPTileSource source) {
+  switch (source) {
+    case ntp_tiles::NTPTileSource::TOP_SITES:
+    case ntp_tiles::NTPTileSource::SUGGESTIONS_SERVICE:
+      return true;
+#if defined(OS_ANDROID)
+    case ntp_tiles::NTPTileSource::POPULAR:
+    case ntp_tiles::NTPTileSource::WHITELIST:
+      return true;
+#else
+    case ntp_tiles::NTPTileSource::POPULAR:
+      return false;
+    case ntp_tiles::NTPTileSource::WHITELIST:
+      // TODO(sfiera): support WHITELIST.
+      return false;
+#endif
+  }
+  NOTREACHED();
+  return false;
+}
+
+std::unique_ptr<ntp_tiles::MostVisitedSites>
+ChromeNTPTilesInternalsMessageHandlerClient::MakeMostVisitedSites() {
+  // TODO(sfiera): share with Android and Instant in a factory.
+  auto* profile = Profile::FromWebUI(web_ui());
+  return base::MakeUnique<ntp_tiles::MostVisitedSites>(
+      GetPrefs(), TopSitesFactory::GetForProfile(profile),
+      suggestions::SuggestionsServiceFactory::GetForProfile(profile),
+      MakePopularSites(),
+      base::MakeUnique<ntp_tiles::IconCacher>(
+          FaviconServiceFactory::GetForProfile(
+              profile, ServiceAccessType::IMPLICIT_ACCESS),
+          base::MakeUnique<image_fetcher::ImageFetcherImpl>(
+              base::MakeUnique<suggestions::ImageDecoderImpl>(),
+              profile->GetRequestContext())),
+      /*supervisor=*/nullptr);
+}
+
+std::unique_ptr<ntp_tiles::PopularSites>
+ChromeNTPTilesInternalsMessageHandlerClient::MakePopularSites() {
+#if defined(OS_ANDROID)
+  return ChromePopularSites::NewForProfile(Profile::FromWebUI(web_ui()));
+#else
+  return nullptr;
+#endif
+}
+
+PrefService* ChromeNTPTilesInternalsMessageHandlerClient::GetPrefs() {
+  return Profile::FromWebUI(web_ui())->GetPrefs();
+}
+
+void ChromeNTPTilesInternalsMessageHandlerClient::RegisterMessageCallback(
+    const std::string& message,
+    const base::Callback<void(const base::ListValue*)>& callback) {
+  web_ui()->RegisterMessageCallback(message, callback);
+}
+
+void ChromeNTPTilesInternalsMessageHandlerClient::CallJavascriptFunctionVector(
+    const std::string& name,
+    const std::vector<const base::Value*>& values) {
+  web_ui()->CallJavascriptFunctionUnsafe(name, values);
+}
+
+content::WebUIDataSource* CreateNTPTilesInternalsHTMLSource() {
+  content::WebUIDataSource* source =
+      content::WebUIDataSource::Create(chrome::kChromeUINTPTilesInternalsHost);
+
+  source->AddResourcePath("ntp_tiles_internals.js", IDR_NTP_TILES_INTERNALS_JS);
+  source->AddResourcePath("ntp_tiles_internals.css",
+                          IDR_NTP_TILES_INTERNALS_CSS);
+  source->SetDefaultResource(IDR_NTP_TILES_INTERNALS_HTML);
+  return source;
+}
+
+}  // namespace
+
+NTPTilesInternalsUI::NTPTilesInternalsUI(content::WebUI* web_ui)
+    : WebUIController(web_ui) {
+  content::WebUIDataSource::Add(Profile::FromWebUI(web_ui),
+                                CreateNTPTilesInternalsHTMLSource());
+  web_ui->AddMessageHandler(new ChromeNTPTilesInternalsMessageHandlerClient);
+}
+
+NTPTilesInternalsUI::~NTPTilesInternalsUI() {}

chrome/browser/ui/webui/ntp_tiles_internals_ui.h

+// 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.
+
+#ifndef CHROME_BROWSER_UI_WEBUI_NTP_TILES_INTERNALS_UI_H_
+#define CHROME_BROWSER_UI_WEBUI_NTP_TILES_INTERNALS_UI_H_
+
+#include "base/macros.h"
+#include "content/public/browser/web_ui_controller.h"
+
+// The implementation for the chrome://ntp-tiles-internals page.
+class NTPTilesInternalsUI : public content::WebUIController {
+ public:
+  explicit NTPTilesInternalsUI(content::WebUI* web_ui);
+  ~NTPTilesInternalsUI() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NTPTilesInternalsUI);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_NTP_TILES_INTERNALS_UI_H_

chrome/common/url_constants.cc

@@ -74,6 +74,7 @@ const char kChromeUINaClURL[] = "chrome://nacl/";
 const char kChromeUINetInternalsURL[] = "chrome://net-internals/";
 const char kChromeUINewProfileURL[] = "chrome://newprofile/";
 const char kChromeUINewTabURL[] = "chrome://newtab/";
+const char kChromeUINTPTilesInternalsURL[] = "chrome://ntp-tiles-internals/";
 const char kChromeUIOmniboxURL[] = "chrome://omnibox/";
 const char kChromeUIPluginsURL[] = "chrome://plugins/";
 const char kChromeUIPolicyURL[] = "chrome://policy/";
@@ -224,6 +225,7 @@ const char kChromeUINaClHost[] = "nacl";
 const char kChromeUINetExportHost[] = "net-export";
 const char kChromeUINetInternalsHost[] = "net-internals";
 const char kChromeUINewTabHost[] = "newtab";
+const char kChromeUINTPTilesInternalsHost[] = "ntp-tiles-internals";
 const char kChromeUIOmniboxHost[] = "omnibox";
 const char kChromeUIPasswordManagerInternalsHost[] =
     "password-manager-internals";
@@ -646,6 +648,7 @@ const char* const kChromeHostURLs[] = {
     kChromeUIProfilerHost,
     kChromeUISignInInternalsHost,
     kChromeUISiteEngagementHost,
+    kChromeUINTPTilesInternalsHost,
     kChromeUISuggestionsHost,
     kChromeUISupervisedUserInternalsHost,
     kChromeUISyncInternalsHost,

chrome/common/url_constants.h

@@ -64,6 +64,7 @@ extern const char kChromeUINaClURL[];
 extern const char kChromeUINetInternalsURL[];
 extern const char kChromeUINewProfileURL[];
 extern const char kChromeUINewTabURL[];
+extern const char kChromeUINTPTilesInternalsURL[];
 extern const char kChromeUIOmniboxURL[];
 extern const char kChromeUIPasswordManagerInternalsHost[];
 extern const char kChromeUIPluginsURL[];
@@ -206,6 +207,7 @@ extern const char kChromeUINaClHost[];
 extern const char kChromeUINetExportHost[];
 extern const char kChromeUINetInternalsHost[];
 extern const char kChromeUINewTabHost[];
+extern const char kChromeUINTPTilesInternalsHost[];
 extern const char kChromeUIOfflineInternalsHost[];
 extern const char kChromeUIOmniboxHost[];
 extern const char kChromeUIPluginsHost[];

components/ntp_tiles/BUILD.gn

@@ -29,8 +29,12 @@ static_library("ntp_tiles") {
     "pref_names.h",
     "switches.cc",
     "switches.h",
+    "webui/ntp_tiles_internals_message_handler.cc",
+    "webui/ntp_tiles_internals_message_handler.h",
+    "webui/ntp_tiles_internals_message_handler_client.h",
     "webui/popular_sites_internals_message_handler.cc",
     "webui/popular_sites_internals_message_handler.h",
+    "webui/popular_sites_internals_message_handler_client.h",
   ]
 
   public_deps = [

components/ntp_tiles/popular_sites.cc

@@ -101,56 +101,6 @@ std::string GetVariationVersion() {
                                             "version");
 }
 
-// Determine the country code to use. In order of precedence:
-// - The explicit "override country" pref set by the user.
-// - The country code from the field trial config (variation parameter).
-// - The Google country code if Google is the default search engine (and the
-//   "--enable-ntp-search-engine-country-detection" switch is present).
-// - The country provided by the VariationsService.
-// - A default fallback.
-std::string GetCountryToUse(const PrefService* prefs,
-                            const TemplateURLService* template_url_service,
-                            VariationsService* variations_service) {
-  std::string country_code =
-      prefs->GetString(ntp_tiles::prefs::kPopularSitesOverrideCountry);
-
-  if (country_code.empty())
-    country_code = GetVariationCountry();
-
-  if (country_code.empty())
-    country_code = GetDefaultSearchEngineCountryCode(template_url_service);
-
-  if (country_code.empty() && variations_service)
-    country_code = variations_service->GetStoredPermanentCountry();
-
-#if defined(OS_IOS)
-  if (country_code.empty())
-    country_code = GetDeviceCountryCode();
-#endif
-
-  if (country_code.empty())
-    country_code = kPopularSitesDefaultCountryCode;
-
-  return base::ToUpperASCII(country_code);
-}
-
-// Determine the version to use. In order of precedence:
-// - The explicit "override version" pref set by the user.
-// - The version from the field trial config (variation parameter).
-// - A default fallback.
-std::string GetVersionToUse(const PrefService* prefs) {
-  std::string version =
-      prefs->GetString(ntp_tiles::prefs::kPopularSitesOverrideVersion);
-
-  if (version.empty())
-    version = GetVariationVersion();
-
-  if (version.empty())
-    version = kPopularSitesDefaultVersion;
-
-  return version;
-}
-
 // Must run on the blocking thread pool.
 bool WriteJsonToFile(const base::FilePath& local_path,
                      const base::Value* json) {
@@ -213,14 +163,7 @@ void PopularSites::StartFetch(bool force_download,
       base::TimeDelta::FromHours(kPopularSitesRedownloadIntervalHours);
   const bool download_time_is_future = base::Time::Now() < last_download_time;
 
-  const std::string country =
-      GetCountryToUse(prefs_, template_url_service_, variations_);
-  const std::string version = GetVersionToUse(prefs_);
-
-  const GURL override_url =
-      GURL(prefs_->GetString(ntp_tiles::prefs::kPopularSitesOverrideURL));
-  pending_url_ = override_url.is_valid() ? override_url
-                                         : GetPopularSitesURL(country, version);
+  pending_url_ = GetURLToUse();
   const bool url_changed =
       pending_url_.spec() != prefs_->GetString(kPopularSitesURLPref);
 
@@ -251,6 +194,64 @@ GURL PopularSites::LastURL() const {
   return GURL(prefs_->GetString(kPopularSitesURLPref));
 }
 
+GURL PopularSites::GetURLToUse() {
+  const std::string country = GetCountryToUse();
+  const std::string version = GetVersionToUse();
+
+  const GURL override_url =
+      GURL(prefs_->GetString(ntp_tiles::prefs::kPopularSitesOverrideURL));
+  return override_url.is_valid() ? override_url
+                                 : GetPopularSitesURL(country, version);
+}
+
+// Determine the country code to use. In order of precedence:
+// - The explicit "override country" pref set by the user.
+// - The country code from the field trial config (variation parameter).
+// - The Google country code if Google is the default search engine (and the
+//   "--enable-ntp-search-engine-country-detection" switch is present).
+// - The country provided by the VariationsService.
+// - A default fallback.
+std::string PopularSites::GetCountryToUse() {
+  std::string country_code =
+      prefs_->GetString(ntp_tiles::prefs::kPopularSitesOverrideCountry);
+
+  if (country_code.empty())
+    country_code = GetVariationCountry();
+
+  if (country_code.empty())
+    country_code = GetDefaultSearchEngineCountryCode(template_url_service_);
+
+  if (country_code.empty() && variations_)
+    country_code = variations_->GetStoredPermanentCountry();
+
+#if defined(OS_IOS)
+  if (country_code.empty())
+    country_code = GetDeviceCountryCode();
+#endif
+
+  if (country_code.empty())
+    country_code = kPopularSitesDefaultCountryCode;
+
+  return base::ToUpperASCII(country_code);
+}
+
+// Determine the version to use. In order of precedence:
+// - The explicit "override version" pref set by the user.
+// - The version from the field trial config (variation parameter).
+// - A default fallback.
+std::string PopularSites::GetVersionToUse() {
+  std::string version =
+      prefs_->GetString(ntp_tiles::prefs::kPopularSitesOverrideVersion);
+
+  if (version.empty())
+    version = GetVariationVersion();
+
+  if (version.empty())
+    version = kPopularSitesDefaultVersion;
+
+  return version;
+}
+
 // static
 void PopularSites::RegisterProfilePrefs(
     user_prefs::PrefRegistrySyncable* user_prefs) {

components/ntp_tiles/popular_sites.h

@@ -94,6 +94,11 @@ class PopularSites : public net::URLFetcherDelegate {
 
   const base::FilePath& local_path() const { return local_path_; }
 
+  // Public for diagnostic pages only.
+  GURL GetURLToUse();
+  std::string GetCountryToUse();
+  std::string GetVersionToUse();
+
   // Register preferences used by this class.
   static void RegisterProfilePrefs(
       user_prefs::PrefRegistrySyncable* user_prefs);

components/ntp_tiles/webui/ntp_tiles_internals_message_handler.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 "components/ntp_tiles/webui/ntp_tiles_internals_message_handler.h"
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/logging.h"
+#include "base/memory/ptr_util.h"
+#include "base/values.h"
+#include "components/ntp_tiles/most_visited_sites.h"
+#include "components/ntp_tiles/pref_names.h"
+#include "components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h"
+#include "components/prefs/pref_service.h"
+#include "components/url_formatter/url_fixer.h"
+#include "url/gurl.h"
+
+namespace ntp_tiles {
+
+NTPTilesInternalsMessageHandlerClient::NTPTilesInternalsMessageHandlerClient() =
+    default;
+NTPTilesInternalsMessageHandlerClient::
+    ~NTPTilesInternalsMessageHandlerClient() = default;
+
+NTPTilesInternalsMessageHandler::NTPTilesInternalsMessageHandler()
+    : client_(nullptr), site_count_(8) {}
+
+NTPTilesInternalsMessageHandler::~NTPTilesInternalsMessageHandler() = default;
+
+void NTPTilesInternalsMessageHandler::RegisterMessages(
+    NTPTilesInternalsMessageHandlerClient* client) {
+  client_ = client;
+
+  client_->RegisterMessageCallback(
+      "registerForEvents",
+      base::Bind(&NTPTilesInternalsMessageHandler::HandleRegisterForEvents,
+                 base::Unretained(this)));
+
+  client_->RegisterMessageCallback(
+      "update", base::Bind(&NTPTilesInternalsMessageHandler::HandleUpdate,
+                           base::Unretained(this)));
+}
+
+void NTPTilesInternalsMessageHandler::HandleRegisterForEvents(
+    const base::ListValue* args) {
+  DCHECK(args->empty());
+
+  SendSourceInfo();
+
+  most_visited_sites_ = client_->MakeMostVisitedSites();
+  most_visited_sites_->SetMostVisitedURLsObserver(this, site_count_);
+}
+
+void NTPTilesInternalsMessageHandler::HandleUpdate(
+    const base::ListValue* args) {
+  const base::DictionaryValue* dict = nullptr;
+  DCHECK_EQ(1u, args->GetSize());
+  args->GetDictionary(0, &dict);
+  DCHECK(dict);
+
+  PrefService* prefs = client_->GetPrefs();
+
+  if (client_->DoesSourceExist(ntp_tiles::NTPTileSource::POPULAR)) {
+    std::string url;
+    dict->GetString("popular.overrideURL", &url);
+    if (url.empty()) {
+      prefs->ClearPref(ntp_tiles::prefs::kPopularSitesOverrideURL);
+    } else {
+      prefs->SetString(ntp_tiles::prefs::kPopularSitesOverrideURL,
+                       url_formatter::FixupURL(url, std::string()).spec());
+    }
+
+    std::string country;
+    dict->GetString("popular.overrideCountry", &country);
+    if (country.empty()) {
+      prefs->ClearPref(ntp_tiles::prefs::kPopularSitesOverrideCountry);
+    } else {
+      prefs->SetString(ntp_tiles::prefs::kPopularSitesOverrideCountry, country);
+    }
+
+    std::string version;
+    dict->GetString("popular.overrideVersion", &version);
+    if (version.empty()) {
+      prefs->ClearPref(ntp_tiles::prefs::kPopularSitesOverrideVersion);
+    } else {
+      prefs->SetString(ntp_tiles::prefs::kPopularSitesOverrideVersion, version);
+    }
+  }
+
+  // Recreate to pick up new values.
+  // TODO(sfiera): refresh MostVisitedSites without re-creating it, as soon as
+  // that will pick up changes to the Popular Sites overrides.
+  most_visited_sites_ = client_->MakeMostVisitedSites();
+  most_visited_sites_->SetMostVisitedURLsObserver(this, site_count_);
+  SendSourceInfo();
+}
+
+void NTPTilesInternalsMessageHandler::SendSourceInfo() {
+  PrefService* prefs = client_->GetPrefs();
+  base::DictionaryValue value;
+
+  value.SetBoolean("topSites",
+                   client_->DoesSourceExist(NTPTileSource::TOP_SITES));
+  value.SetBoolean(
+      "suggestionsService",
+      client_->DoesSourceExist(NTPTileSource::SUGGESTIONS_SERVICE));
+  value.SetBoolean("whitelist",
+                   client_->DoesSourceExist(NTPTileSource::WHITELIST));
+
+  if (client_->DoesSourceExist(NTPTileSource::POPULAR)) {
+    auto popular_sites = client_->MakePopularSites();
+    value.SetString("popular.url", popular_sites->GetURLToUse().spec());
+    value.SetString("popular.country", popular_sites->GetCountryToUse());
+    value.SetString("popular.version", popular_sites->GetVersionToUse());
+
+    value.SetString(
+        "popular.overrideURL",
+        prefs->GetString(ntp_tiles::prefs::kPopularSitesOverrideURL));
+    value.SetString(
+        "popular.overrideCountry",
+        prefs->GetString(ntp_tiles::prefs::kPopularSitesOverrideCountry));
+    value.SetString(
+        "popular.overrideVersion",
+        prefs->GetString(ntp_tiles::prefs::kPopularSitesOverrideVersion));
+  } else {
+    value.SetBoolean("popular", false);
+  }
+
+  client_->CallJavascriptFunction(
+      "chrome.ntp_tiles_internals.receiveSourceInfo", value);
+}
+
+void NTPTilesInternalsMessageHandler::SendTiles(const NTPTilesVector& tiles) {
+  auto sites_list = base::MakeUnique<base::ListValue>();
+  for (const NTPTile& tile : tiles) {
+    auto entry = base::MakeUnique<base::DictionaryValue>();
+    entry->SetString("title", tile.title);
+    entry->SetString("url", tile.url.spec());
+    entry->SetInteger("source", static_cast<int>(tile.source));
+    entry->SetString("whitelistIconPath",
+                     tile.whitelist_icon_path.LossyDisplayName());
+    sites_list->Append(std::move(entry));
+  }
+
+  base::DictionaryValue result;
+  result.Set("sites", std::move(sites_list));
+  client_->CallJavascriptFunction("chrome.ntp_tiles_internals.receiveSites",
+                                  result);
+}
+
+void NTPTilesInternalsMessageHandler::OnMostVisitedURLsAvailable(
+    const NTPTilesVector& tiles) {
+  SendTiles(tiles);
+}
+
+void NTPTilesInternalsMessageHandler::OnIconMadeAvailable(
+    const GURL& site_url) {}
+
+}  // namespace ntp_tiles

components/ntp_tiles/webui/ntp_tiles_internals_message_handler.h

+// 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.
+
+#ifndef COMPONENTS_NTP_TILES_WEBUI_NTP_TILES_INTERNALS_MESSAGE_HANDLER_H_
+#define COMPONENTS_NTP_TILES_WEBUI_NTP_TILES_INTERNALS_MESSAGE_HANDLER_H_
+
+#include <memory>
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "components/ntp_tiles/most_visited_sites.h"
+
+namespace base {
+class ListValue;
+}  // namespace base
+
+namespace ntp_tiles {
+
+class MostVisitedSites;
+class NTPTilesInternalsMessageHandlerClient;
+
+// Implements the WebUI message handler for chrome://ntp-tiles-internals/
+//
+// Because content and iOS use different implementations of WebUI, this class
+// implements the generic portion and depends on the embedder to inject a bridge
+// to the embedder's API. It cannot itself implement either API directly.
+class NTPTilesInternalsMessageHandler : public MostVisitedSites::Observer {
+ public:
+  NTPTilesInternalsMessageHandler();
+  ~NTPTilesInternalsMessageHandler() override;
+
+  // Called when the WebUI page's JavaScript has loaded and it is ready to
+  // receive RegisterMessageCallback() calls. |client| must outlive this object.
+  void RegisterMessages(NTPTilesInternalsMessageHandlerClient* client);
+
+ private:
+  // Callbacks registered in RegisterMessages().
+  void HandleRegisterForEvents(const base::ListValue* args);
+  void HandleUpdate(const base::ListValue* args);
+
+  void SendSourceInfo();
+  void SendTiles(const NTPTilesVector& tiles);
+
+  // MostVisitedSites::Observer.
+  void OnMostVisitedURLsAvailable(const NTPTilesVector& tiles) override;
+  void OnIconMadeAvailable(const GURL& site_url) override;
+
+  // Bridge to embedder's API.
+  NTPTilesInternalsMessageHandlerClient* client_;
+
+  int site_count_;
+  std::unique_ptr<MostVisitedSites> most_visited_sites_;
+
+  DISALLOW_COPY_AND_ASSIGN(NTPTilesInternalsMessageHandler);
+};
+
+}  // namespace ntp_tiles
+
+#endif  // COMPONENTS_NTP_TILES_WEBUI_NTP_TILES_INTERNALS_MESSAGE_HANDLER_H_

components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.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 "components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h"
+
+namespace ntp_tiles {
+
+NTPTilesInternalsMessageHandlerClient::NTPTilesInternalsMessageHandlerClient() =
+    default;
+NTPTilesInternalsMessageHandlerClient::
+    ~NTPTilesInternalsMessageHandlerClient() = default;
+
+}  // namespace ntp_tiles

components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h

+// 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.
+
+#ifndef COMPONENTS_NTP_TILES_WEBUI_NTP_TILES_INTERNALS_MESSAGE_HANDLER_CLIENT_H_
+#define COMPONENTS_NTP_TILES_WEBUI_NTP_TILES_INTERNALS_MESSAGE_HANDLER_CLIENT_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "base/callback_forward.h"
+#include "base/macros.h"
+#include "components/ntp_tiles/ntp_tile_source.h"
+
+class PrefService;
+
+namespace base {
+class Value;
+class ListValue;
+}  // namespace base
+
+namespace ntp_tiles {
+
+class MostVisitedSites;
+class PopularSites;
+
+// Implemented by embedders to hook up NTPTilesInternalsMessageHandler.
+class NTPTilesInternalsMessageHandlerClient {
+ public:
+  // Returns the PrefService for the embedder and containing WebUI page.
+  virtual PrefService* GetPrefs() = 0;
+
+  // Returns true if the given source is enabled (even if, in practice, none of
+  // the tiles would come from it).
+  virtual bool DoesSourceExist(NTPTileSource source) = 0;
+
+  // Creates a new MostVisitedSites based on the context pf the WebUI page.
+  virtual std::unique_ptr<ntp_tiles::MostVisitedSites>
+  MakeMostVisitedSites() = 0;
+
+  // Creates a new PopularSites based on the context pf the WebUI page.
+  virtual std::unique_ptr<ntp_tiles::PopularSites> MakePopularSites() = 0;
+
+  // Registers a callback in Javascript. See content::WebUI and web::WebUIIOS.
+  virtual void RegisterMessageCallback(
+      const std::string& message,
+      const base::Callback<void(const base::ListValue*)>& callback) = 0;
+
+  // Invokes a function in Javascript. See content::WebUI and web::WebUIIOS.
+  virtual void CallJavascriptFunctionVector(
+      const std::string& name,
+      const std::vector<const base::Value*>& values) = 0;
+
+  // Convenience function for CallJavascriptFunctionVector().
+  template <typename... Arg>
+  void CallJavascriptFunction(const std::string& name, const Arg&... arg) {
+    CallJavascriptFunctionVector(name, {&arg...});
+  }
+
+ protected:
+  NTPTilesInternalsMessageHandlerClient();
+  virtual ~NTPTilesInternalsMessageHandlerClient();
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NTPTilesInternalsMessageHandlerClient);
+};
+
+}  // namespace ntp_tiles
+
+#endif  // COMPONENTS_NTP_TILES_WEBUI_NTP_TILES_INTERNALS_MESSAGE_HANDLER_CLIENT_H_

components/ntp_tiles/webui/resources/ntp_tiles_internals.css

+/* 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. */
+
+html {
+  font-size: 20px;
+}
+
+div.section {
+  width: 100%;
+  display: inline-block;
+  margin-left: auto;
+  margin-right: auto;
+}
+
+div.section.hidden {
+  display: none;
+}
+
+h2 {
+  color: rgb(74, 142, 230);
+  font-size: 100%;
+  margin-bottom: 0;
+}
+
+.err {
+  color: red;
+}
+
+.section-details {
+  width: 100%;
+}
+
+.section-details th {
+  background: rgb(239, 243, 255);
+}
+
+.section-details td {
+  vertical-align: top;
+}
+
+.section-details td.detail {
+  text-align: right;
+  width: 1px;
+  white-space: nowrap;
+}
+
+.section-details td.value input {
+  width: 100%;
+}
+
+#json-value {
+  font-size: 75%;
+}

components/ntp_tiles/webui/resources/ntp_tiles_internals.html

+<!--
+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.
+-->
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<if expr="is_android or is_ios">
+<meta name="viewport" content="width=device-width, initial-scale=1.0">
+</if>
+<title>NTP Tiles Internals</title>
+<link rel="stylesheet" href="chrome://resources/css/text_defaults.css">
+<link rel="stylesheet" href="chrome://resources/css/list.css">
+<link rel="stylesheet" href="ntp_tiles_internals.css">
+<script src="chrome://resources/js/cr.js"></script>
+<script src="chrome://resources/js/jstemplate_compiled.js"></script>
+<script src="chrome://resources/js/load_time_data.js"></script>
+<script src="chrome://resources/js/util.js"></script>
+<if expr="is_ios">
+<!-- TODO(crbug.com/487000): Remove this once injected by web. -->
+<script src="chrome://resources/js/ios/web_ui.js"></script>
+</if>
+<script src="ntp_tiles_internals.js"></script>
+</head>
+
+<body>
+<div>
+  <div id="sources" class="section">
+    <h2>Sources</h2>
+    <table class="section-details">
+      <tbody jsselect="topSites">
+        <tr>
+          <th colspan="2">TOP_SITES</th>
+        </tr>
+        <tr>
+          <td class="detail">enabled</td>
+          <td class="value" jsdisplay="$this">yes</td>
+          <td class="value" jsdisplay="!$this">no</td>
+        </tr>
+        <tr>
+          <th colspan="2">SUGGESTIONS_SERVICE</th>
+        </tr>
+      </tbody>
+      <tbody jsselect="suggestionsService">
+        <tr>
+          <td class="detail">enabled</td>
+          <td class="value" jsdisplay="$this">yes</td>
+          <td class="value" jsdisplay="!$this">no</td>
+        </tr>
+      </tbody>
+      <tbody jsselect="popular">
+        <tr>
+          <th colspan="2">POPULAR</th>
+        </tr>
+        <tr jsdisplay="$this">
+          <td class="detail">URL</td>
+          <td class="value"><input id="override-url" type="text" jsvalues="value:overrideURL;placeholder:url"></td>
+        </tr>
+        <tr jsdisplay="$this">
+          <td class="detail">Country</td>
+          <td class="value"><input id="override-country" type="text" jsvalues="value:overrideCountry;placeholder:country"></td>
+        </tr>
+        <tr jsdisplay="$this">
+          <td class="detail">Version</td>
+          <td class="value"><input id="override-version" type="text" jsvalues="values:overrideVersion;placeholder:version"></td>
+        </tr>
+        <tr jsdisplay="!$this">
+          <td class="detail">enabled</td>
+          <td class="value">no</td>
+        </tr>
+      </tbody>
+      <tbody jsselect="whitelist">
+        <tr>
+          <th colspan="2">WHITELIST</th>
+        </tr>
+        <tr>
+          <td class="detail">enabled</td>
+          <td class="value" jsdisplay="$this">yes</td>
+          <td class="value" jsdisplay="!$this">no</td>
+        </tr>
+        <tr jsskip="true">
+          <th colspan="2"><input id="submit-update" type="submit" value="Update"></input></th>
+        </tr>
+      </tbody>
+    </table>
+  </div>
+
+  <div id="sites" class="section">
+    <h2>Sites</h2>
+    <table class="section-details">
+      <tbody jsselect="sites">
+        <tr>
+          <th colspan="2" jscontent="title"></th>
+        </tr>
+        <tr>
+          <td class="detail">Source</td>
+          <td class="value" jsdisplay="source &lt; 0">???</td>
+          <td class="value" jsdisplay="source == 0">TOP_SITES</td>
+          <td class="value" jsdisplay="source == 1">SUGGESTIONS_SERVICE</td>
+          <td class="value" jsdisplay="source == 2">POPULAR</td>
+          <td class="value" jsdisplay="source == 3">WHITELIST</td>
+          <td class="value" jsdisplay="source &gt; 3">???</td>
+        </tr>
+        <tr>
+          <td class="detail">URL</td>
+          <td class="value"><a jsvalues="href:url" jscontent="url"></a></td>
+        </tr>
+      </tbody>
+    </table>
+  </div>
+</div>
+
+</body>
+</html>
+

components/ntp_tiles/webui/resources/ntp_tiles_internals.js

+// 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.
+
+cr.define('chrome.ntp_tiles_internals', function() {
+  'use strict';
+
+  var initialize = function() {
+    receiveSites({});
+
+    $('submit-update').addEventListener('click', function(event) {
+      event.preventDefault();
+      chrome.send('update', [{
+        "popular": {
+          "overrideURL": $('override-url').value,
+          "overrideCountry": $('override-country').value,
+          "overrideVersion": $('override-version').value,
+        },
+      }])
+    });
+
+    chrome.send('registerForEvents');
+  }
+
+  var receiveSourceInfo = function(state) {
+    jstProcess(new JsEvalContext(state), $('sources'));
+  }
+
+  var receiveSites = function(sites) {
+    jstProcess(new JsEvalContext(sites), $('sites'));
+  }
+
+  // Return an object with all of the exports.
+  return {
+    initialize: initialize,
+    receiveSourceInfo: receiveSourceInfo,
+    receiveSites: receiveSites,
+  };
+});
+
+document.addEventListener('DOMContentLoaded',
+                          chrome.ntp_tiles_internals.initialize);
+

components/resources/OWNERS

@@ -21,7 +21,7 @@ per-file gcm_driver_resources.grdp=peter@chromium.org
 per-file gcm_driver_resources.grdp=zea@chromium.org
 per-file neterror*=mmenke@chromium.org
 per-file neterror*=juliatuttle@chromium.org
-per-file ntp_tiles.grdp=file://components/ntp_tiles/OWNERS
+per-file ntp_tiles_resources.grdp=file://components/ntp_tiles/OWNERS
 per-file proximity_auth*=tengs@chromium.org
 per-file supervised_user_error_page.grpd=aberent@chromium.org
 per-file supervised_user_error_page.grpd=bauerb@chromium.org

components/resources/ntp_tiles_resources.grdp

@@ -5,4 +5,7 @@
     <include name="IDR_POPULAR_SITES_INTERNALS_JS" file="../ntp_tiles/webui/resources/popular_sites_internals.js" type="BINDATA" />
     <include name="IDR_POPULAR_SITES_INTERNALS_CSS" file="../ntp_tiles/webui/resources/popular_sites_internals.css" type="BINDATA" />
   </if>
+  <include name="IDR_NTP_TILES_INTERNALS_HTML" file="../ntp_tiles/webui/resources/ntp_tiles_internals.html" flattenhtml="true" allowexternalscript="true" type="BINDATA" />
+  <include name="IDR_NTP_TILES_INTERNALS_JS" file="../ntp_tiles/webui/resources/ntp_tiles_internals.js" type="BINDATA" />
+  <include name="IDR_NTP_TILES_INTERNALS_CSS" file="../ntp_tiles/webui/resources/ntp_tiles_internals.css" type="BINDATA" />
 </grit-part>

ios/chrome/browser/chrome_url_constants.cc

@@ -17,6 +17,7 @@ const char kChromeUICreditsURL[] = "chrome://credits/";
 const char kChromeUIFlagsURL[] = "chrome://flags/";
 const char kChromeUIHistoryURL[] = "chrome://history/";
 const char kChromeUINewTabURL[] = "chrome://newtab/";
+const char kChromeUINTPTilesInternalsURL[] = "chrome://ntp-tiles-internals/";
 const char kChromeUIOfflineURL[] = "chrome://offline/";
 const char kChromeUIPhysicalWebURL[] = "chrome://physical-web/";
 const char kChromeUIPopularSitesInternalsURL[] =
@@ -39,6 +40,7 @@ const char kChromeUIHistoryFrameHost[] = "history-frame";
 const char kChromeUIHistoryHost[] = "history";
 const char kChromeUINetExportHost[] = "net-export";
 const char kChromeUINewTabHost[] = "newtab";
+const char kChromeUINTPTilesInternalsHost[] = "ntp-tiles-internals";
 const char kChromeUIOfflineHost[] = "offline";
 const char kChromeUIOmahaHost[] = "omaha";
 const char kChromeUIPhysicalWebHost[] = "physical-web";
@@ -53,13 +55,13 @@ const char kChromeUIVersionHost[] = "version";
 // These hosts will also be suggested by BuiltinProvider.
 // 'histograms' is chrome WebUI on iOS, content WebUI on other platforms.
 const char* const kChromeHostURLs[] = {
-    kChromeUIBookmarksHost,             kChromeUIChromeURLsHost,
-    kChromeUICreditsHost,               kChromeUIFlagsHost,
-    kChromeUIHistogramHost,             kChromeUINetExportHost,
-    kChromeUINewTabHost,                kChromeUISignInInternalsHost,
-    kChromeUISyncInternalsHost,         kChromeUIPhysicalWebHost,
-    kChromeUIPopularSitesInternalsHost, kChromeUITermsHost,
-    kChromeUIVersionHost,
+    kChromeUIBookmarksHost,       kChromeUIChromeURLsHost,
+    kChromeUICreditsHost,         kChromeUIFlagsHost,
+    kChromeUIHistogramHost,       kChromeUINetExportHost,
+    kChromeUINewTabHost,          kChromeUINTPTilesInternalsHost,
+    kChromeUISignInInternalsHost, kChromeUISyncInternalsHost,
+    kChromeUIPhysicalWebHost,     kChromeUIPopularSitesInternalsHost,
+    kChromeUITermsHost,           kChromeUIVersionHost,
 };
 const size_t kNumberOfChromeHostURLs = arraysize(kChromeHostURLs);
 

ios/chrome/browser/chrome_url_constants.h

@@ -27,6 +27,7 @@ extern const char kChromeUICreditsURL[];
 extern const char kChromeUIFlagsURL[];
 extern const char kChromeUIHistoryURL[];
 extern const char kChromeUINewTabURL[];
+extern const char kChromeUINTPTilesInternalsURL[];
 extern const char kChromeUIOfflineURL[];
 extern const char kChromeUIPhysicalWebURL[];
 extern const char kChromeUIPopularSitesInternalsURL[];
@@ -49,6 +50,7 @@ extern const char kChromeUIHistoryFrameHost[];
 extern const char kChromeUIHistoryHost[];
 extern const char kChromeUINetExportHost[];
 extern const char kChromeUINewTabHost[];
+extern const char kChromeUINTPTilesInternalsHost[];
 extern const char kChromeUIOfflineHost[];
 extern const char kChromeUIOmahaHost[];
 extern const char kChromeUIPhysicalWebHost[];

ios/chrome/browser/ui/webui/BUILD.gn

@@ -12,6 +12,8 @@ source_set("webui") {
     "flags_ui.cc",
     "flags_ui.h",
     "mojo_web_ui_ios_controller.h",
+    "ntp_tiles_internals_ui.cc",
+    "ntp_tiles_internals_ui.h",
     "physical_web_ui.cc",
     "physical_web_ui.h",
     "popular_sites_internals_ui.cc",

ios/chrome/browser/ui/webui/ntp_tiles_internals_ui.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 "ios/chrome/browser/ui/webui/ntp_tiles_internals_ui.h"
+
+#include "components/grit/components_resources.h"
+#include "components/ntp_tiles/field_trial.h"
+#include "components/ntp_tiles/most_visited_sites.h"
+#include "components/ntp_tiles/popular_sites.h"
+#include "components/ntp_tiles/webui/ntp_tiles_internals_message_handler.h"
+#include "components/ntp_tiles/webui/ntp_tiles_internals_message_handler_client.h"
+#include "ios/chrome/browser/browser_state/chrome_browser_state.h"
+#include "ios/chrome/browser/chrome_url_constants.h"
+#include "ios/chrome/browser/ntp_tiles/ios_most_visited_sites_factory.h"
+#include "ios/chrome/browser/ntp_tiles/ios_popular_sites_factory.h"
+#include "ios/web/public/web_thread.h"
+#include "ios/web/public/web_ui_ios_data_source.h"
+#include "ios/web/public/webui/web_ui_ios.h"
+#include "ios/web/public/webui/web_ui_ios_message_handler.h"
+
+namespace {
+
+// The implementation for the chrome://ntp-tiles-internals page.
+class IOSNTPTilesInternalsMessageHandlerBridge
+    : public web::WebUIIOSMessageHandler,
+      public ntp_tiles::NTPTilesInternalsMessageHandlerClient {
+ public:
+  IOSNTPTilesInternalsMessageHandlerBridge() {}
+
+ private:
+  // web::WebUIIOSMessageHandler:
+  void RegisterMessages() override;
+
+  // ntp_tiles::NTPTilesInternalsMessageHandlerClient
+  bool DoesSourceExist(ntp_tiles::NTPTileSource source) override;
+  std::unique_ptr<ntp_tiles::MostVisitedSites> MakeMostVisitedSites() override;
+  std::unique_ptr<ntp_tiles::PopularSites> MakePopularSites() override;
+  PrefService* GetPrefs() override;
+  void RegisterMessageCallback(
+      const std::string& message,
+      const base::Callback<void(const base::ListValue*)>& callback) override;
+  void CallJavascriptFunctionVector(
+      const std::string& name,
+      const std::vector<const base::Value*>& values) override;
+
+  ntp_tiles::NTPTilesInternalsMessageHandler handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(IOSNTPTilesInternalsMessageHandlerBridge);
+};
+
+void IOSNTPTilesInternalsMessageHandlerBridge::RegisterMessages() {
+  handler_.RegisterMessages(this);
+}
+
+bool IOSNTPTilesInternalsMessageHandlerBridge::DoesSourceExist(
+    ntp_tiles::NTPTileSource source) {
+  switch (source) {
+    case ntp_tiles::NTPTileSource::TOP_SITES:
+    case ntp_tiles::NTPTileSource::SUGGESTIONS_SERVICE:
+    case ntp_tiles::NTPTileSource::POPULAR:
+      return true;
+    case ntp_tiles::NTPTileSource::WHITELIST:
+      return false;
+  }
+  NOTREACHED();
+  return false;
+}
+
+std::unique_ptr<ntp_tiles::MostVisitedSites>
+IOSNTPTilesInternalsMessageHandlerBridge::MakeMostVisitedSites() {
+  return IOSMostVisitedSitesFactory::NewForBrowserState(
+      ios::ChromeBrowserState::FromWebUIIOS(web_ui()));
+}
+
+std::unique_ptr<ntp_tiles::PopularSites>
+IOSNTPTilesInternalsMessageHandlerBridge::MakePopularSites() {
+  return IOSPopularSitesFactory::NewForBrowserState(
+      ios::ChromeBrowserState::FromWebUIIOS(web_ui()));
+}
+
+PrefService* IOSNTPTilesInternalsMessageHandlerBridge::GetPrefs() {
+  return ios::ChromeBrowserState::FromWebUIIOS(web_ui())->GetPrefs();
+}
+
+void IOSNTPTilesInternalsMessageHandlerBridge::RegisterMessageCallback(
+    const std::string& message,
+    const base::Callback<void(const base::ListValue*)>& callback) {
+  web_ui()->RegisterMessageCallback(message, callback);
+}
+
+void IOSNTPTilesInternalsMessageHandlerBridge::CallJavascriptFunctionVector(
+    const std::string& name,
+    const std::vector<const base::Value*>& values) {
+  web_ui()->CallJavascriptFunction(name, values);
+}
+
+}  // namespace
+
+web::WebUIIOSDataSource* CreateNTPTilesInternalsHTMLSource() {
+  web::WebUIIOSDataSource* source =
+      web::WebUIIOSDataSource::Create(kChromeUINTPTilesInternalsHost);
+
+  source->AddResourcePath("ntp_tiles_internals.js", IDR_NTP_TILES_INTERNALS_JS);
+  source->AddResourcePath("ntp_tiles_internals.css",
+                          IDR_NTP_TILES_INTERNALS_CSS);
+  source->SetDefaultResource(IDR_NTP_TILES_INTERNALS_HTML);
+  return source;
+}
+
+NTPTilesInternalsUI::NTPTilesInternalsUI(web::WebUIIOS* web_ui)
+    : web::WebUIIOSController(web_ui) {
+  web::WebUIIOSDataSource::Add(ios::ChromeBrowserState::FromWebUIIOS(web_ui),
+                               CreateNTPTilesInternalsHTMLSource());
+  web_ui->AddMessageHandler(new IOSNTPTilesInternalsMessageHandlerBridge);
+}
+
+NTPTilesInternalsUI::~NTPTilesInternalsUI() {}

ios/chrome/browser/ui/webui/ntp_tiles_internals_ui.h

+// 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.
+
+#ifndef IOS_CHROME_BROWSER_UI_WEBUI_NTP_TILES_INTERNALS_UI_H_
+#define IOS_CHROME_BROWSER_UI_WEBUI_NTP_TILES_INTERNALS_UI_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "ios/web/public/webui/web_ui_ios_controller.h"
+
+// The WebUI handler for chrome://ntp-tiles-internals.
+class NTPTilesInternalsUI : public web::WebUIIOSController {
+ public:
+  explicit NTPTilesInternalsUI(web::WebUIIOS* web_ui);
+  ~NTPTilesInternalsUI() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(NTPTilesInternalsUI);
+};
+
+#endif  // IOS_CHROME_BROWSER_UI_WEBUI_NTP_TILES_INTERNALS_UI_H_