Add chrome side webusb permission UI code

chrome/browser/ui/website_settings/chooser_bubble_delegate.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_BUBBLE_DELEGATE_H_
+#define CHROME_BROWSER_UI_WEBSITE_SETTINGS_CHOOSER_BUBBLE_DELEGATE_H_
+
+#include "base/macros.h"
+#include "chrome/browser/ui/website_settings/chooser_options.h"

[Jeffrey Yasskin, 2015/12/05 01:13:53]

You can forward declare this type.

[juncai, 2015/12/07 18:28:47]

Done.

+#include "components/bubble/bubble_delegate.h"
+
+class ChooserBubbleUiView;

[Jeffrey Yasskin, 2015/12/05 01:13:53]

Don't forward-declare classes that aren't used in this header.

[juncai, 2015/12/07 18:28:47]

Done.

+
+class ChooserBubbleDelegate : public BubbleDelegate {

[Jeffrey Yasskin, 2015/12/05 01:13:53]

What does this class do? What's its lifetime?

[juncai, 2015/12/07 18:28:47]

This class implements class BubbleDelegate:
https://code.google.com/p/chromium/codesearch#chromium/src/components/bubble/...
which defines a bubble. And it is owned by BubbleControler by passing it as a
scoped_ptr to its constructor:
https://code.google.com/p/chromium/codesearch#chromium/src/components/bubble/...

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

Write down what kind of bubble this class defines. We can see from the code that
it implements BubbleDelegate, but we can't see why or how folks are supposed to
use it. You need to comment that. e.g. "Subclass ChooserBubbleDelegate to
implement a chooser bubble, which has some introductory text and a list of
options that users can pick one of. Create an instance of your subclass and pass
it to BubbleManager::ShowBubble() to show the bubble. Your subclass must fill in
chooser_options_ to define the set of options users can pick from. You can also
override GetName() to xyz." (except fix anything I've gotten wrong)
You need to say how users of the class have to use it, in order to avoid using
it after it's been destroyed. For example, are users allowed to call back into
this object after Select(), Close(), or Cancel() is called?

+ public:
+  ChooserBubbleDelegate();
+  ~ChooserBubbleDelegate() override;
+
+  // BubbleDelegate:
+  std::string GetName() const override;
+
+  virtual void Select(int index) = 0;

[Jeffrey Yasskin, 2015/12/05 01:13:53]

When are these functions called? How do subclasses need to override them?

[juncai, 2015/12/07 18:28:47]

The ChooserBubbleUiView/ChooserBubbleUiCocoa class holds a pointer of
ChooserBubbleDelegate, and it is called when user clicks "Connect" button which
grants permission.
https://codereview.chromium.org/1408193003/diff/530001/chrome/browser/ui/view...
https://codereview.chromium.org/1473393003/diff/60001/chrome/browser/ui/cocoa...
Usually subclass such as UsbChooserBubbleDelegate/BluetoothChooserBubbleDelegate
can override this function to grant permission to user's choice. In the
UsbChooserBubbleDelegate/BluetoothChooserBubbleDelegate implementation, it calls
ChooserOptions::Select.

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

These functions need comments saying that, so future maintainers can read the
code to understand them.

I'd write something like:

  // These three functions are called just before this object is destroyed:
  // Called when the user selects the |index|th element of |chooser_options_|
from the dialog.
  virtual void Select(int index) = 0;
  // Called when the user presses the 'Cancel' button in the dialog.
  virtual void Cancel() = 0;
  // Called when the user clicks outside the dialog or the dialog otherwise
closes without the user taking an explicit action.
  virtual void Close() = 0;

+  virtual void Cancel() = 0;
+  virtual void Close() = 0;
+
+ protected:
+  scoped_ptr<ChooserOptions> chooser_options_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ChooserBubbleDelegate);
+};
+
+#endif  // CHROME_BROWSER_UI_WEBSITE_SETTINGS_CHOOSER_BUBBLE_DELEGATE_H_