Fix Windows XP and Vista taskbar activation issue.

ui/views/widget/native_widget_win.cc

Index: ui/views/widget/native_widget_win.cc
diff --git a/ui/views/widget/native_widget_win.cc b/ui/views/widget/native_widget_win.cc
index 24273dd2f7afe41c74b025a0cc9ad32dd90b20ce..6c65886a37bae6d3869250366ccc58c9088ea296 100644
--- a/ui/views/widget/native_widget_win.cc
+++ b/ui/views/widget/native_widget_win.cc
@@ -1712,8 +1712,10 @@ LRESULT NativeWidgetWin::OnNCActivate(BOOL active) {
   if (IsActive())
     delegate_->EnableInactiveRendering();
 
-  // Avoid DefWindowProc non-client rendering over our custom frame.
-  if (!GetWidget()->ShouldUseNativeFrame()) {
+  // Avoid DefWindowProc non-client rendering over our custom frame on newer
+  // Windows versions only (breaks taskbar activation indication on XP/Vista).
+  if (!GetWidget()->ShouldUseNativeFrame() &&
+      base::win::GetVersion() > base::win::VERSION_VISTA) {
     SetMsgHandled(TRUE);
     return TRUE;
   }