Add CombinedDesktopMediaList class

chrome/browser/media/tab_desktop_media_list.h

+// Copyright 2016 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_MEDIA_TAB_DESKTOP_MEDIA_LIST_H_
+#define CHROME_BROWSER_MEDIA_TAB_DESKTOP_MEDIA_LIST_H_
+
+#include <map>
+#include <vector>
+
+#include "chrome/browser/media/desktop_media_list_base.h"
+
+namespace gfx {
+class Image;
+}
+
+// Implementation of DesktopMediaList that shows tab/WebContents.
+class TabDesktopMediaList : public DesktopMediaListBase {
+ public:
+  TabDesktopMediaList();
+  ~TabDesktopMediaList() override;
+
+  void SetFakeSourcesForTesting(std::vector<SourceDescription>& sources,

[qiangchen, 2016/01/26 01:01:50]

Put ForTesting function in private and add the class that needs to call this
function as TabDesktopMediaList's friend.

[GeorgeZ, 2016/01/27 00:17:39]

Done.

+                                std::vector<gfx::Image>& favicons);
+
+ private:
+  typedef std::map<content::DesktopMediaID, uint32_t> ImageHashesMap;
+
+  void Refresh() override;
+
+  ImageHashesMap favicon_hashes_;
+
+  // For unit tests.
+  std::vector<SourceDescription> fake_sources_;
+  std::vector<gfx::Image> fake_favicons_;
+};
+
+#endif  // CHROME_BROWSER_MEDIA_TAB_DESKTOP_MEDIA_LIST_H_