Clear the cached avatar button offset when the DPI scaling changes

chrome/browser/ui/views/frame/minimize_button_metrics_win.cc

 // 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.
 
 #include "chrome/browser/ui/views/frame/minimize_button_metrics_win.h"
 
 #include "base/i18n/rtl.h"
 #include "base/logging.h"
 #include "base/win/windows_version.h"
 #include "dwmapi.h"
@@ skipping 69 matching lines @@
   DCHECK(!hwnd_);
   hwnd_ = hwnd;
 }
 
 void MinimizeButtonMetrics::OnHWNDActivated() {
   was_activated_ = true;
   // NOTE: we don't cache here as it seems only after the activate is the value
   // correct.
 }
 
+void MinimizeButtonMetrics::OnDpiChanged() {
+  // This ensures that the next time GetMinimizeButtonOffsetX() is called, it
+  // will be recalculated, given the new scale factor.
+  cached_minimize_button_x_delta_ = 0;
+}
+
 // This function attempts to calculate the odd and varying difference
 // between the results of DwmGetWindowAttribute with the
 // DWMWA_CAPTION_BUTTON_BOUNDS flag and the information from the
 // WM_GETTITLEBARINFOEX message. It will return an empirically determined
 // offset until the window has been activated and the message returns
 // valid rectangles.
 int MinimizeButtonMetrics::GetButtonBoundsPositionOffset(
     const RECT& button_bounds,
     const RECT& window_bounds) const {
   if (button_bounds_position_offset_ == kInvalidOffset) {
@@ skipping 106 matching lines @@
     cached_minimize_button_x_delta_ = minimize_button_offset;
   } else {
     RECT client_rect = {0};
     GetClientRect(hwnd_, &client_rect);
     cached_minimize_button_x_delta_ =
         client_rect.right - minimize_button_offset;
   }
   last_cached_minimize_button_x_delta_ = cached_minimize_button_x_delta_;
   return minimize_button_offset;
 }