Serve chrome://apps from a regular WebUIDataSource.

Previously because of the long history of this page (which at some
point served as the NTP, aka NTP4) it was served by a custom class
which delegated logic to NTPResourceCache. There is no good reason to
use the NTPResourceCache for chrome://apps anymore, AFAIK.

Using a WebUIDataSource makes a lot of things simpler, like registering
resources, localized strings, load time data, and many more.

This is in preparation of possibly migrating chrome://apps to JS modules
(TBD). Regardless, moving away from NTPResourceCache is a positive step.

Bug: 1168053
Change-Id: If82d634c8d7e699dc1c906517c23c40bfaa0b6b8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2629855Reviewed-by: Esmael Elmoslimany <aee@chromium.org>
Commit-Queue: dpapad <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#846035}

chrome/browser/resources/ntp4/new_tab.html

@@ -16,6 +16,8 @@
 <link id="themecss" rel="stylesheet">
 <script src="../../../../ui/webui/resources/js/assert.js"></script>
 <script src="../../../../ui/webui/resources/js/util.js"></script>
+<script src="../../../../ui/webui/resources/js/load_time_data.js"></script>
+<script src="chrome://apps/strings.js"></script>
 <script>
 // Until themes can clear the cache, force-reload the theme stylesheet.
 $('themecss').href = 'chrome://theme/css/new_tab_theme.css?' + Date.now();

chrome/browser/ui/webui/app_launcher_page_ui.h

@@ -6,7 +6,7 @@
 #define CHROME_BROWSER_UI_WEBUI_APP_LAUNCHER_PAGE_UI_H_
 
 #include "base/macros.h"
-#include "content/public/browser/url_data_source.h"
+#include "components/prefs/pref_change_registrar.h"
 #include "content/public/browser/web_ui_controller.h"
 #include "ui/base/layout.h"
 
@@ -31,32 +31,10 @@ class AppLauncherPageUI : public content::WebUIController {
                                   const base::ListValue& args) override;
 
  private:
-  class HTMLSource : public content::URLDataSource {
-   public:
-    explicit HTMLSource(Profile* profile);
-    ~HTMLSource() override;
-
-    // content::URLDataSource implementation.
-    std::string GetSource() override;
-    void StartDataRequest(
-        const GURL& url,
-        const content::WebContents::Getter& wc_getter,
-        content::URLDataSource::GotDataCallback callback) override;
-    std::string GetMimeType(const std::string&) override;
-    bool ShouldReplaceExistingSource() override;
-    bool AllowCaching() override;
-    std::string GetContentSecurityPolicy(
-        network::mojom::CSPDirectiveName directive) override;
-
-   private:
-
-    // Pointer back to the original profile.
-    Profile* profile_;
-
-    DISALLOW_COPY_AND_ASSIGN(HTMLSource);
-  };
+  void OnHideWebStoreIconChanged();
 
   Profile* GetProfile() const;
+  PrefChangeRegistrar pref_change_registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(AppLauncherPageUI);
 };

chrome/browser/ui/webui/ntp/app_launcher_handler.cc

@@ -404,11 +404,12 @@ void AppLauncherHandler::CreateExtensionInfo(const Extension* extension,
 }
 
 // static
-void AppLauncherHandler::GetLocalizedValues(Profile* profile,
-                                            base::DictionaryValue* values) {
+void AppLauncherHandler::RegisterLoadTimeData(
+    Profile* profile,
+    content::WebUIDataSource* source) {
   PrefService* prefs = profile->GetPrefs();
   int shown_page = prefs->GetInteger(prefs::kNtpShownPage);
-  values->SetInteger("shown_page_index", shown_page & INDEX_MASK);
+  source->AddInteger("shown_page_index", shown_page & INDEX_MASK);
 }
 
 // static

chrome/browser/ui/webui/ntp/app_launcher_handler.h

@@ -25,6 +25,7 @@
 #include "components/sync/model/string_ordinal.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
+#include "content/public/browser/web_ui_data_source.h"
 #include "content/public/browser/web_ui_message_handler.h"
 #include "extensions/browser/extension_registry_observer.h"
 #include "extensions/common/extension.h"
@@ -69,8 +70,8 @@ class AppLauncherHandler
                            base::DictionaryValue* value);
 
   // Registers values (strings etc.) for the page.
-  static void GetLocalizedValues(Profile* profile,
-                                 base::DictionaryValue* values);
+  static void RegisterLoadTimeData(Profile* profile,
+                                   content::WebUIDataSource* source);
 
   // Register per-profile preferences.
   static void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry);