views::Textfield: Implement yank editing command.

ui/views/controls/textfield/textfield_model.h

 // Copyright 2014 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.
 
 #ifndef UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_MODEL_H_
 #define UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_MODEL_H_
 
 #include <stddef.h>
 
 #include <list>
@@ skipping 77 matching lines @@
   void ReplaceChar(base::char16 c) {
     ReplaceTextInternal(base::string16(&c, 1), true);
   }
 
   // Appends the text.
   // The current composition text will be confirmed.
   void Append(const base::string16& new_text);
 
   // Deletes the first character after the current cursor position (as if, the
   // the user has pressed delete key in the textfield). Returns true if
-  // the deletion is successful.
+  // the deletion is successful. If |add_to_kill_buffer| is true, the deleted
+  // text is copied to the kill buffer.
   // If there is composition text, it'll be deleted instead.
-  bool Delete();
+  bool Delete(bool add_to_kill_buffer = false);
 
   // Deletes the first character before the current cursor position (as if, the
   // the user has pressed backspace key in the textfield). Returns true if
-  // the removal is successful.
+  // the removal is successful. If |add_to_kill_buffer| is true, the deleted
+  // text is copied to the kill buffer.
   // If there is composition text, it'll be deleted instead.
-  bool Backspace();
+  bool Backspace(bool add_to_kill_buffer = false);
 
   // Cursor related methods.
 
   // Returns the current cursor position.
   size_t GetCursorPosition() const;
 
   // Moves the cursor, see RenderText for additional details.
   // The current composition text will be confirmed.
   void MoveCursor(gfx::BreakType break_type,
                   gfx::VisualCursorDirection direction,
@@ skipping 58 matching lines @@
 
   // Pastes text from the clipboard at current cursor position. Returns true
   // if any text is pasted.
   bool Paste();
 
   // Transposes the characters to either side of the insertion point and
   // advances the insertion point past both of them. Returns true if text is
   // changed.
   bool Transpose();
 
+  // Pastes text from the kill buffer at the current cursor position or
+  // selection.
+  bool Yank();
+
   // Tells if any text is selected, even if the selection is in composition
   // text.
   bool HasSelection() const;
 
   // Deletes the selected text. This method shouldn't be called with
   // composition text.
   void DeleteSelection();
 
   // Deletes the selected text (if any) and insert text at given position.
   void DeleteSelectionAndInsertTextAt(const base::string16& new_text,
@@ skipping 99 matching lines @@
   //   2) new edit is added. (redo history is cleared)
   //   3) redone all undone edits.
   EditHistory::iterator current_edit_;
 
   DISALLOW_COPY_AND_ASSIGN(TextfieldModel);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_TEXTFIELD_TEXTFIELD_MODEL_H_