Enable custom MIME types in web copy/paste.

ui/base/clipboard/clipboard_aurax11.cc

Index: ui/base/clipboard/clipboard_aurax11.cc
diff --git a/ui/base/clipboard/clipboard_aurax11.cc b/ui/base/clipboard/clipboard_aurax11.cc
index a6c2c5709bc76f85b43adc17172f7777cf6e9031..4e16aefe855ddf4a0ae51a7f0e9e6754bdfb1230 100644
--- a/ui/base/clipboard/clipboard_aurax11.cc
+++ b/ui/base/clipboard/clipboard_aurax11.cc
@@ -15,6 +15,8 @@ namespace ui {
 namespace {
 const char kMimeTypeBitmap[] = "image/bmp";
 const char kMimeTypeWebkitSmartPaste[] = "chromium/x-webkit-paste";
+// TODO(dcheng): This name is temporary. See crbug.com/106449
+const char kMimeTypeWebCustomData[] = "chromium/x-web-custom-data";
 
 // ClipboardData contains data copied to the Clipboard for a variety of formats.
 // It mostly just provides APIs to cleanly access and manipulate this data.
@@ -331,4 +333,9 @@ Clipboard::FormatType Clipboard::GetWebKitSmartPasteFormatType() {
   return std::string(kMimeTypeWebkitSmartPaste);
 }
 
+// static
+Clipboard::FormatType Clipboard::GetWebCustomDataFormatType() {
+  return std::string(kMimeTypeWebCustomData);
+}
+
 }  // namespace ui