Have Chrome draw top window border when using custom titlebar.

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

Index: chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc
diff --git a/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc b/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc
index 406f558591156c6dcc7fb37d47dec0a7aa77d122..19379f26039b6e0c2a3f6e1a588fbc984f8746ea 100644
--- a/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc
+++ b/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc
@@ -199,6 +199,11 @@ void BrowserDesktopWindowTreeHostWin::PostHandleMSG(UINT message,
       }
       break;
     }
+    case WM_DWMCOLORIZATIONCOLORCHANGED:
+      // Activation border may have changed color.
+      if (GetWidget()->non_client_view())

[Peter Kasting, 2016/10/01 05:00:14]

Nit: Consider a temp (maybe with auto*) to avoid duplicated calls here (but if
so, consider also fixing the WM_WINDOWPOSCHANGED case similarly).

+        GetWidget()->non_client_view()->SchedulePaint();
+      break;
   }
 }