Remove implementation of Panels on OSes other than ChromeOS.

chrome/browser/ui/views/panels/taskbar_window_thumbnailer_win.h

-// Copyright (c) 2012 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_VIEWS_PANELS_TASKBAR_WINDOW_THUMBNAILER_WIN_H_
-#define CHROME_BROWSER_UI_VIEWS_PANELS_TASKBAR_WINDOW_THUMBNAILER_WIN_H_
-
-#include <memory>
-#include <vector>
-
-#include "base/macros.h"
-#include "ui/base/win/hwnd_subclass.h"
-
-class SkBitmap;
-
-class TaskbarWindowThumbnailerDelegateWin {
- public:
-  // Returns the list of handles for all windows that are used to construct the
-  // thumbnail. If empty list is returned, the snapshot of current window
-  // is used.
-  virtual std::vector<HWND> GetSnapshotWindowHandles() const = 0;
-};
-
-// Provides the custom thumbnail and live preview for the window that appears
-// in the taskbar (Windows 7 and later).
-class TaskbarWindowThumbnailerWin : public ui::HWNDMessageFilter {
- public:
-  TaskbarWindowThumbnailerWin(HWND hwnd,
-                              TaskbarWindowThumbnailerDelegateWin* delegate);
-  ~TaskbarWindowThumbnailerWin() override;
-
-  // Starts using the custom snapshot for live preview. The snapshot is only
-  // captured once when the system requests it, so the updates of the panels'
-  // content will not be automatically reflected in the thumbnail.
-  void Start();
-
-  // Stops providing the custom snapshot for live preview.
-  void Stop();
-
-  // Captures the snapshot now instead of when the system requests it.
-  void CaptureSnapshot();
-
-  // Invalidates the snapshot such that a fresh copy can be obtained next time
-  // when the system requests it.
-  void InvalidateSnapshot();
-
-  // Provide the snapshot to the new window. If the snapshot is captured for the
-  // old window, it will also be used for the new window.
-  void ReplaceWindow(HWND new_hwnd);
-
- private:
-  // Overridden from ui::HWNDMessageFilter:
-  bool FilterMessage(HWND hwnd,
-                     UINT message,
-                     WPARAM w_param,
-                     LPARAM l_param,
-                     LRESULT* l_result) override;
-
-  // Message handlers.
-  bool OnDwmSendIconicThumbnail(int width, int height, LRESULT* l_result);
-  bool OnDwmSendIconicLivePreviewBitmap(LRESULT* l_result);
-
-  // Captures and returns the screenshot of the window. The caller is
-  // responsible to release the returned SkBitmap instance.
-  SkBitmap* CaptureWindowImage() const;
-
-  HWND hwnd_;
-  TaskbarWindowThumbnailerDelegateWin* delegate_;  // Weak, owns us.
-  std::unique_ptr<SkBitmap> capture_bitmap_;
-
-  DISALLOW_COPY_AND_ASSIGN(TaskbarWindowThumbnailerWin);
-};
-
-#endif  // CHROME_BROWSER_UI_VIEWS_PANELS_TASKBAR_WINDOW_THUMBNAILER_WIN_H_