Have ScopedClipboardWriter and Clipboard::WriteObjects take a buffer parameter.

ui/base/clipboard/clipboard_gtk.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/base/clipboard/clipboard.h"
 
 #include <gtk/gtk.h>
 #include <X11/extensions/Xfixes.h>
 #include <X11/Xatom.h>
 #include <map>
@@ skipping 200 matching lines @@
 
 Clipboard::Clipboard() : clipboard_data_(NULL) {
   clipboard_ = gtk_clipboard_get(GDK_SELECTION_CLIPBOARD);
   primary_selection_ = gtk_clipboard_get(GDK_SELECTION_PRIMARY);
 }
 
 Clipboard::~Clipboard() {
   gtk_clipboard_store(clipboard_);
 }
 
-void Clipboard::WriteObjects(const ObjectMap& objects) {
+void Clipboard::WriteObjects(Buffer buffer, const ObjectMap& objects) {
   clipboard_data_ = new TargetMap();
 
   for (ObjectMap::const_iterator iter = objects.begin();
        iter != objects.end(); ++iter) {
     DispatchObject(static_cast<ObjectType>(iter->first), iter->second);
   }
 
-  SetGtkClipboard();
+  SetGtkClipboard(buffer);
 }
 
 // When a URL is copied from a render view context menu (via "copy link
 // location", for example), we additionally stick it in the X clipboard. This
 // matches other linux browsers.
 void Clipboard::DidWriteURL(const std::string& utf8_text) {
   gtk_clipboard_set_text(primary_selection_, utf8_text.c_str(),
                          utf8_text.length());
 }
 
 // Take ownership of the GTK clipboard and inform it of the targets we support.
-void Clipboard::SetGtkClipboard() {
+void Clipboard::SetGtkClipboard(Buffer buffer) {
   scoped_array<GtkTargetEntry> targets(
       new GtkTargetEntry[clipboard_data_->size()]);
 
   int i = 0;
   for (Clipboard::TargetMap::iterator iter = clipboard_data_->begin();
        iter != clipboard_data_->end(); ++iter, ++i) {
     targets[i].target = const_cast<char*>(iter->first.c_str());
     targets[i].flags = 0;
     targets[i].info = 0;
   }
 
-  if (gtk_clipboard_set_with_data(clipboard_, targets.get(),
+  GtkClipboard *clipboard = LookupBackingClipboard(buffer);
+
+  if (gtk_clipboard_set_with_data(clipboard, targets.get(),
                                   clipboard_data_->size(),
                                   GetData, ClearData,
                                   clipboard_data_)) {
-    gtk_clipboard_set_can_store(clipboard_,
+    gtk_clipboard_set_can_store(clipboard,
                                 targets.get(),
                                 clipboard_data_->size());
   }
 
   // clipboard_data_ now owned by the GtkClipboard.
   clipboard_data_ = NULL;
 }
 
 void Clipboard::WriteText(const char* text_data, size_t text_len) {
   char* data = new char[text_len];
@@ skipping 346 matching lines @@
       return clipboard_;
     case BUFFER_SELECTION:
       return primary_selection_;
     default:
       NOTREACHED();
       return NULL;
   }
 }
 
 }  // namespace ui