Add chrome side webusb permission UI code

chrome/browser/ui/website_settings/chooser_options.h

+// Copyright 2015 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_WEBSITE_SETTINGS_CHOOSER_OPTIONS_H_
+#define CHROME_BROWSER_UI_WEBSITE_SETTINGS_CHOOSER_OPTIONS_H_
+
+#include <string>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/strings/string16.h"
+
+// Stores all the available chooser options, handle options initialization,
+// option added/removed.
+class ChooserOptions {
+ public:
+  ChooserOptions() {}
+  virtual ~ChooserOptions() {}
+
+  class Observer {
+   public:
+    virtual void OnOptionsInitialized() = 0;

[Jeffrey Yasskin, 2015/12/07 23:57:55]

Is there a guarantee that OnOptionsInitialized() is only called once?

[juncai, 2015/12/08 20:16:29]

Yes, it is called only once at the ChooserBubbleDelegate subclass's constructor.

+    virtual void OnOptionAdded(int index) = 0;
+    virtual void OnOptionRemoved(int index) = 0;
+
+   protected:
+    virtual ~Observer() {}
+  };
+
+  virtual const std::vector<base::string16>& GetOptions() const = 0;
+  virtual void Select(int index) = 0;

[Jeffrey Yasskin, 2015/12/07 23:57:54]

Does a call to Select() indicate that the ChooserOptions is about to be
destroyed?

[juncai, 2015/12/08 20:16:29]

Yes.

+
+  void set_observer(Observer* observer) { observer_ = observer; }
+  Observer* observer() const { return observer_; }
+
+ private:
+  Observer* observer_ = nullptr;
+  DISALLOW_COPY_AND_ASSIGN(ChooserOptions);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBSITE_SETTINGS_CHOOSER_OPTIONS_H_