Clear the clipboard closing Incognito window

ui/base/clipboard/clipboard.cc

Index: ui/base/clipboard/clipboard.cc
diff --git a/ui/base/clipboard/clipboard.cc b/ui/base/clipboard/clipboard.cc
index 2473723e35939c99a4f1190be70a24b5df851f44..8a7be8f5d583d7e7d68503db48c3f682407f9305 100644
--- a/ui/base/clipboard/clipboard.cc
+++ b/ui/base/clipboard/clipboard.cc
@@ -153,6 +153,11 @@ void Clipboard::DestroyClipboardForCurrentThread() {
   }
 }
 
+void Clipboard::WriteObjects(Buffer buffer, const ObjectMap& objects) {
+  WriteObjectsImpl(buffer, objects);
+  FOR_EACH_OBSERVER(ClipboardObserver, observer_list_, OnWriteObjects(buffer));
+}
+
 void Clipboard::DispatchObject(ObjectType type, const ObjectMapParams& params) {
   // All types apart from CBF_WEBKIT need at least 1 non-empty param.
   if (type != CBF_WEBKIT && (params.empty() || params[0].empty()))
@@ -228,6 +233,13 @@ void Clipboard::DispatchObject(ObjectType type, const ObjectMapParams& params) {
           params[1].size());
       break;
 
+    case CBF_INCOGNITO_MARKER:
+#if defined(TOOLKIT_GTK)  // TODO(vasilii): support other platforms.
+      WriteData(GetIncognitoMarkerFormatType(),
+                &params[0].front(), params[0].size());
+#endif
+      break;
+
     default:
       NOTREACHED();
   }