Mark drags starting in web content as tainted to avoid file path forgery

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 dde85fe723dd86378dcf3c331ce9e078ec70d405..70768444b0cc4dc5b0ec78746b86291f68950b1a 100644
--- a/ui/base/clipboard/clipboard_aurax11.cc
+++ b/ui/base/clipboard/clipboard_aurax11.cc
@@ -762,8 +762,11 @@ void Clipboard::WriteBookmark(const char* title_data,
 // Write an extra flavor that signifies WebKit was the last to modify the
 // pasteboard. This flavor has no data.
 void Clipboard::WriteWebSmartPaste() {
-  aurax11_details_->InsertMapping(kMimeTypeWebkitSmartPaste,
-                                  scoped_refptr<base::RefCountedMemory>());
+  std::string empty;
+  aurax11_details_->InsertMapping(
+      kMimeTypeWebkitSmartPaste,
+      scoped_refptr<base::RefCountedMemory>(
+          base::RefCountedString::TakeString(&empty)));

[tony, 2014/03/21 23:09:00]

This doesn't seem related to the bug fix.  If you want to include it, mention it
in the change description.

Why do you need to pass the empty string?

[dcheng, 2014/03/21 23:57:07]

It's not directly related. I can pull it out--I did this for consistency, since
this was the code I originally copied in the Aura X11 OSExchangeData::Provider
implementation.

You need to pass something or we unconditionally try to deref the
RefCountedMemory in OnSelectionRequest, which crashes if the pointer is null
like here.

[tony, 2014/03/22 00:15:05]

This is fine, but please mention this in the change description.

 }
 
 void Clipboard::WriteBitmap(const SkBitmap& bitmap) {