Add a path for content/ to open and control a Bluetooth chooser dialog.

content/public/browser/bluetooth_chooser.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 CONTENT_PUBLIC_BROWSER_BLUETOOTH_CHOOSER_H_
+#define CONTENT_PUBLIC_BROWSER_BLUETOOTH_CHOOSER_H_
+
+#include <string>
+
+#include "base/callback.h"
+#include "base/strings/string16.h"
+#include "content/common/content_export.h"
+
+namespace content {
+
+// Represents a way to ask the user to select a Bluetooth device from a list of
+// options.
+class CONTENT_EXPORT BluetoothChooser {
+ public:
+  enum class Event {
+    // The user cancelled the chooser instead of selecting a device.
+    CANCELLED,
+    // The user selected device |opt_device_id|.
+    SELECTED,
+
+    // As the dialog implementations grow more user-visible buttons and knobs,
+    // we'll add enumerators here to support them.
+  };
+
+  // Chooser implementations are constructed with an |EventHandler| and report
+  // user interaction with the chooser through it. |opt_device_id| is an empty
+  // string except for Event::SELECTED.
+  //
+  // The EventHandler won't be called after the chooser object is destroyed.
+  //
+  // After the EventHandler is called with Event::CANCELLED or Event::SELECTED,
+  // it won't be called again, and users must not call any more BluetoothChooser
+  // methods.
+  typedef base::Callback<void(Event, const std::string& opt_device_id)>
+      EventHandler;
+
+  // |observer| must outlive |this|. |chooser_id| is propagated to the Observer

[jam, 2015/08/25 23:45:50]

nit: no more observer

[Jeffrey Yasskin, 2015/08/26 00:19:01]

Whoops, thanks.

+  // methods.
+  BluetoothChooser() {}
+  virtual ~BluetoothChooser();
+
+  // Lets the chooser tell the user the state of the Bluetooth adapter. This
+  // defaults to POWERED_ON.
+  enum class AdapterPresence { ABSENT, POWERED_OFF, POWERED_ON };
+  virtual void SetAdapterPresence(AdapterPresence presence) {}
+
+  // Lets the chooser tell the user whether discovery is happening. This
+  // defaults to DISCOVERING.
+  enum class DiscoveryState { FAILED_TO_START, DISCOVERING, IDLE };
+  virtual void ShowDiscoveryState(DiscoveryState state) {}
+
+  // Shows a new device in the chooser.
+  virtual void AddDevice(const std::string& device_id,
+                         const base::string16& device_name) {}
+
+  // Tells the chooser that a device is no longer available. The chooser should
+  // not call DeviceSelected() for a device that's been removed.
+  virtual void RemoveDevice(const std::string& device_id) {}
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_BLUETOOTH_CHOOSER_H_