Make Mandoline shut down cleanly.

ui/platform_window/win/win_window.cc

Index: ui/platform_window/win/win_window.cc
diff --git a/ui/platform_window/win/win_window.cc b/ui/platform_window/win/win_window.cc
index debf105c11a7d4cf73a378adefc2eac2c958e238..af3f49e729fe88339625bd1d5e9e88db7ed3fb1d 100644
--- a/ui/platform_window/win/win_window.cc
+++ b/ui/platform_window/win/win_window.cc
@@ -38,7 +38,7 @@ gfx::Rect GetWindowBoundsForClientBounds(DWORD style, DWORD ex_style,
 
 WinWindow::WinWindow(PlatformWindowDelegate* delegate,
                      const gfx::Rect& bounds)
-    : delegate_(delegate) {
+    : delegate_(delegate), destroyed_(false) {
   CHECK(delegate_);
   if (use_popup_as_root_window_for_test)
     set_window_style(WS_POPUP);
@@ -177,6 +177,11 @@ LRESULT WinWindow::OnCreate(CREATESTRUCT* create_struct) {
 }
 
 void WinWindow::OnDestroy() {
+  if (destroyed_)

[Ben Goodger (Google), 2015/05/13 20:21:07]

Instead we should make ~WinWindow not call Destroy(). This may result in some
other code not closing the window but we should find those and change them to
call Close() prior to destructing this object.

[jam, 2015/05/14 14:42:48]

Done.

+    return;
+
+  destroyed_ = true;
+
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION("440919 WinWindow::OnDestroy"));