Minimized panels should not open on Windows when activated by the OS

chrome/browser/ui/panels/panel_browser_view.cc

Index: chrome/browser/ui/panels/panel_browser_view.cc
diff --git a/chrome/browser/ui/panels/panel_browser_view.cc b/chrome/browser/ui/panels/panel_browser_view.cc
index 9873a24b7b06df08190efd61f66d09695053000d..7f7676580f6e0acdbb030deeb44ff54221a9400a 100644
--- a/chrome/browser/ui/panels/panel_browser_view.cc
+++ b/chrome/browser/ui/panels/panel_browser_view.cc
@@ -303,6 +303,24 @@ bool PanelBrowserView::IsPanelActive() const {
   return IsActive();
 }
 
+void PanelBrowserView::PreventActivationByOS(bool prevent_activation) {
+#if defined(OS_WIN) && !defined(USE_AURA)
+  // Set the flags "NoActivate" and "AppWindow" to make sure
+  // the minimized panels do not get activated by the OS, but
+  // do appear in the taskbar and Alt-Tab menu.
+  gfx::NativeWindow native_window = GetNativePanelHandle();
+  int style = ::GetWindowLong(native_window, GWL_EXSTYLE);
+
+  if (prevent_activation)
+    ::SetWindowLong(native_window, GWL_EXSTYLE,
+        style |  WS_EX_NOACTIVATE | WS_EX_APPWINDOW);
+  else // allow activation
+    ::SetWindowLong(native_window, GWL_EXSTYLE,
+        style & ~WS_EX_NOACTIVATE & ~WS_EX_APPWINDOW);
+#endif
+}
+
+
 gfx::NativeWindow PanelBrowserView::GetNativePanelHandle() {
   return GetNativeHandle();
 }