Add a chrome://webapks page.

chrome/browser/ui/webui/webapks_ui.h

Index: chrome/browser/ui/webui/webapks_ui.h
diff --git a/chrome/browser/ui/webui/webapks_ui.h b/chrome/browser/ui/webui/webapks_ui.h
new file mode 100644
index 0000000000000000000000000000000000000000..9cf52a46b98edba2d6496493ca6036c7376e78b6
--- /dev/null
+++ b/chrome/browser/ui/webui/webapks_ui.h
@@ -0,0 +1,21 @@
+// 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.
+
+#ifndef CHROME_BROWSER_UI_WEBUI_WEBAPKS_UI_H_
+#define CHROME_BROWSER_UI_WEBUI_WEBAPKS_UI_H_
+
+#include "base/macros.h"
+#include "content/public/browser/web_ui_controller.h"
+
+// The WebUI handler for chrome://webapks.
+class WebApksUI : public content::WebUIController {
+ public:
+  explicit WebApksUI(content::WebUI* web_ui);
+  ~WebApksUI() override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(WebApksUI);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBUI_WEBAPKS_UI_H_