Add a chrome://webapks page.

chrome/browser/ui/webui/webapks_handler.cc

+// Copyright (c) 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/ui/webui/webapks_handler.h"
+
+#include "base/callback_forward.h"
+#include "chrome/browser/android/shortcut_helper.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/grit/generated_resources.h"
+#include "components/strings/grit/components_strings.h"
+#include "components/webapks_ui/webapks_ui_constants.h"
+#include "content/public/browser/web_ui.h"
+
+WebApksHandler::WebApksHandler() : weak_ptr_factory_(this) {}
+
+WebApksHandler::~WebApksHandler() {}
+
+void WebApksHandler::RegisterMessages() {
+  web_ui()->RegisterMessageCallback(
+      webapks_ui::kRequestWebApksInfo,

[pkotwicz, 2017/01/18 02:08:21]

Nit: You can inline the JS method name here the way that
browsing_history_handler.cc does

[gonzalon, 2017/01/18 15:29:32]

Done.

+      base::Bind(&WebApksHandler::HandleRequestWebApksInfo,
+                 base::Unretained(this)));
+}
+
+void WebApksHandler::HandleRequestWebApksInfo(const base::ListValue* args) {
+  // The WebApkInfoCallback will delete itself after it is done.
+  base::Callback<void(std::vector<WebApkInfo*>)> callback = base::Bind(
+      &WebApksHandler::OnWebApkInfoReceived, weak_ptr_factory_.GetWeakPtr());
+  ShortcutHelper::ListWebApks(base::android::AttachCurrentThread(), callback);
+}
+
+void WebApksHandler::OnWebApkInfoReceived(
+    std::vector<WebApkInfo*> webapks_list) {
+  base::ListValue* list = new base::ListValue();

[pkotwicz, 2017/01/18 02:08:21]

Can you create the value on the stack instead? In Chromium, we generally avoid
raw pointers. We often use std::unique_ptr<> to hold pointers.

In this case, it looks like you can do:
base::ListValue list;

Note that the second parameter in WebUI::CallJavascriptFunctionUnsafe() is a
const reference

[gonzalon, 2017/01/18 15:29:32]

Yeah, not sure why I used so many pointers, it's better this way, thanks for
pointing it out!

+  for (size_t i = 0; i < webapks_list.size(); ++i) {
+    const WebApkInfo* webapk_info = webapks_list[i];
+    std::unique_ptr<base::DictionaryValue> result(new base::DictionaryValue());

[pkotwicz, 2017/01/18 02:08:21]

Awesome! Creating base::DictionaryValue on the heap to avoid a copy on line 44
makes perfect sense

+    result->SetString("shortName", webapk_info->short_name);
+    result->SetString("packageName", webapk_info->package_name);
+    result->SetInteger("shellApkVersion", webapk_info->shell_apk_version);
+    result->SetInteger("versionCode", webapk_info->version_code);
+    delete webapk_info;
+    list->Append(std::move(result));
+  }
+
+  web_ui()->CallJavascriptFunctionUnsafe(webapks_ui::kReturnWebApksInfo, *list);
+}