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..e384c6528d70dbc4bdd01ad8832b5704d1f3864e 100644
--- a/ui/base/clipboard/clipboard.cc
+++ b/ui/base/clipboard/clipboard.cc
@@ -92,6 +92,15 @@ static base::LazyInstance<ClipboardMap> g_clipboard_map =
 static base::LazyInstance<base::Lock>::Leaky
     g_clipboard_map_lock = LAZY_INSTANCE_INITIALIZER;
 
+const std::size_t kSourceTagSize = sizeof(Clipboard::SourceTag);
+
+// The union serves to easily convert SourceTag into its binary representation
+// and vice versa.
+union SourceTag2BinaryHelper {
+  Clipboard::SourceTag tag;
+  uint8 bytes[kSourceTagSize];
+};
+
 }  // namespace
 
 const char Clipboard::kMimeTypeText[] = "text/plain";
@@ -102,6 +111,24 @@ const char Clipboard::kMimeTypeRTF[] = "text/rtf";
 const char Clipboard::kMimeTypePNG[] = "image/png";
 
 // static
+Clipboard::ObjectMapParam Clipboard::SourceTag2Binary(SourceTag tag) {
+  SourceTag2BinaryHelper helper;
+  helper.tag = tag;
+  std::vector<char> bytes(kSourceTagSize);
+  memcpy(&bytes[0], helper.bytes, kSourceTagSize);
+  return bytes;
+}
+
+// static
+Clipboard::SourceTag Clipboard::Binary2SourceTag(const std::string& binary) {
+  if (binary.size() != kSourceTagSize)
+    return SourceTag();
+  SourceTag2BinaryHelper helper;
+  memcpy(helper.bytes, binary.c_str(), kSourceTagSize);
+  return helper.tag;
+}
+
+// static
 void Clipboard::SetAllowedThreads(
     const std::vector<base::PlatformThreadId>& allowed_threads) {
   base::AutoLock lock(g_clipboard_map_lock.Get());
@@ -153,6 +180,14 @@ void Clipboard::DestroyClipboardForCurrentThread() {
   }
 }
 
+void Clipboard::WriteObjects(Buffer buffer,
+                             const ObjectMap& objects,
+                             SourceTag tag) {
+  WriteObjectsImpl(buffer, objects, tag);
+  if (!write_objects_callback_.is_null())
+    write_objects_callback_.Run(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()))