Clear the cached avatar button offset when the DPI scaling changes

chrome/browser/ui/views/frame/browser_desktop_window_tree_host_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_FRAME_BROWSER_DESKTOP_WINDOW_TREE_HOST_WIN_H_
 #define CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_DESKTOP_WINDOW_TREE_HOST_WIN_H_
 
 #include <windows.h>
 #include <uxtheme.h>
 
@@ skipping 28 matching lines @@
   DesktopWindowTreeHost* AsDesktopWindowTreeHost() override;
   int GetMinimizeButtonOffset() const override;
   bool UsesNativeSystemMenu() const override;
 
   // Overridden from DesktopWindowTreeHostWin:
   int GetInitialShowState() const override;
   bool GetClientAreaInsets(gfx::Insets* insets) const override;
   void HandleCreate() override;
   void HandleDestroying() override;
   void HandleFrameChanged() override;
+  void HandleWindowScaleFactorChanged(float window_scale_factor) override;
   bool PreHandleMSG(UINT message,
                     WPARAM w_param,
                     LPARAM l_param,
                     LRESULT* result) override;
   void PostHandleMSG(UINT message, WPARAM w_param, LPARAM l_param) override;
   views::FrameMode GetFrameMode() const override;
   bool ShouldUseNativeFrame() const override;
   bool ShouldWindowContentsBeTransparent() const override;
   void FrameTypeChanged() override;
 
@@ skipping 13 matching lines @@
   std::unique_ptr<views::NativeMenuWin> system_menu_;
 
   // Necessary to avoid corruption on NC paint in Aero mode.
   bool did_gdi_clear_;
 
   DISALLOW_COPY_AND_ASSIGN(BrowserDesktopWindowTreeHostWin);
 };
 
 
 #endif  // CHROME_BROWSER_UI_VIEWS_FRAME_BROWSER_DESKTOP_WINDOW_TREE_HOST_WIN_H_