Try 2 - Change how ui::Clipboard is accessed so there's only one per thread.

ui/views/controls/textfield/textfield_views_model.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/views/controls/textfield/textfield_views_model.h"
 
 #include <algorithm>
 
 #include "base/i18n/break_iterator.h"
 #include "base/logging.h"
 #include "base/stl_util.h"
 #include "base/utf_string_conversions.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/clipboard/scoped_clipboard_writer.h"
 #include "ui/base/native_theme/native_theme.h"
 #include "ui/base/range/range.h"
 #include "ui/base/text/utf16_indexing.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/font.h"
 #include "ui/gfx/render_text.h"
 #include "ui/gfx/text_constants.h"
 #include "ui/views/controls/textfield/textfield.h"
-#include "ui/views/views_delegate.h"
 
 namespace views {
 
 namespace internal {
 
 // An edit object holds enough information/state to undo/redo the
 // change. Two edits are merged when possible, for example, when
 // you type new characters in sequence.  |Commit()| can be used to
 // mark an edit as an independent edit and it shouldn't be merged.
 // (For example, when you did undo/redo, or a text is appended via
@@ skipping 470 matching lines @@
     current_edit_ ++;
   string16 old = GetText();
   size_t old_cursor = GetCursorPosition();
   (*current_edit_)->Redo(this);
   return old != GetText() || old_cursor != GetCursorPosition();
 }
 
 bool TextfieldViewsModel::Cut() {
   if (!HasCompositionText() && HasSelection() && !render_text_->is_obscured()) {
     ui::ScopedClipboardWriter(
-        views::ViewsDelegate::views_delegate->GetClipboard(),
+        ui::Clipboard::GetForCurrentThread(),
         ui::Clipboard::BUFFER_STANDARD).WriteText(GetSelectedText());
     // A trick to let undo/redo handle cursor correctly.
     // Undoing CUT moves the cursor to the end of the change rather
     // than beginning, unlike Delete/Backspace.
     // TODO(oshima): Change Delete/Backspace to use DeleteSelection,
     // update DeleteEdit and remove this trick.
     const ui::Range& selection = render_text_->selection();
     render_text_->SelectRange(ui::Range(selection.end(), selection.start()));
     DeleteSelection();
     return true;
   }
   return false;
 }
 
 bool TextfieldViewsModel::Copy() {
   if (!HasCompositionText() && HasSelection() && !render_text_->is_obscured()) {
     ui::ScopedClipboardWriter(
-        views::ViewsDelegate::views_delegate->GetClipboard(),
+        ui::Clipboard::GetForCurrentThread(),
         ui::Clipboard::BUFFER_STANDARD).WriteText(GetSelectedText());
     return true;
   }
   return false;
 }
 
 bool TextfieldViewsModel::Paste() {
   string16 result;
-  views::ViewsDelegate::views_delegate->GetClipboard()
+  ui::Clipboard::GetForCurrentThread()
       ->ReadText(ui::Clipboard::BUFFER_STANDARD, &result);
   if (!result.empty()) {
     InsertTextInternal(result, false);
     return true;
   }
   return false;
 }
 
 bool TextfieldViewsModel::HasSelection() const {
   return !render_text_->selection().is_empty();
@@ skipping 229 matching lines @@
   if (delete_from != delete_to)
     render_text_->SetText(text.erase(delete_from, delete_to - delete_from));
   if (!new_text.empty())
     render_text_->SetText(text.insert(new_text_insert_at, new_text));
   render_text_->SetCursorPosition(new_cursor_pos);
   // TODO(oshima): mac selects the text that is just undone (but gtk doesn't).
   // This looks fine feature and we may want to do the same.
 }
 
 }  // namespace views