Change signature of |ui::ElideText()|. Add a truncate mode.

ui/base/text/text_elider.h

 // Copyright (c) 2011 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_BASE_TEXT_TEXT_ELIDER_H_
 #define UI_BASE_TEXT_TEXT_ELIDER_H_
 #pragma once
 
 #include <string>
 
@@ skipping 22 matching lines @@
 // Note: in RTL locales, if the URL returned by this function is going to be
 // displayed in the UI, then it is likely that the string needs to be marked
 // as an LTR string (using base::i18n::WrapStringWithLTRFormatting()) so that it
 // is displayed properly in an RTL context. Please refer to
 // http://crbug.com/6487 for more information.
 UI_EXPORT string16 ElideUrl(const GURL& url,
                             const gfx::Font& font,
                             int available_pixel_width,
                             const std::string& languages);
 
-// Elides |text| to fit in |available_pixel_width|.  If |elide_in_middle| is
-// set the ellipsis is placed in the middle of the string; otherwise it is
-// placed at the end.
+enum ElideBehavior {
+  // Add ellipsis at the end of the string.
+  ELIDE_AT_END,
+  // Add ellipsis in the middle of the string.
+  ELIDE_IN_MIDDLE,
+  // Truncate the end of the string.
+  TRUNCATE_AT_END
+};
+
+// Elides |text| to fit in |available_pixel_width| according to the specified
+// |elide_behavior|.
 UI_EXPORT string16 ElideText(const string16& text,
                              const gfx::Font& font,
                              int available_pixel_width,
-                             bool elide_in_middle);
+                             ElideBehavior elide_behavior);
 
 // Elide a filename to fit a given pixel width, with an emphasis on not hiding
 // the extension unless we have to. If filename contains a path, the path will
 // be removed if filename doesn't fit into available_pixel_width. The elided
 // filename is forced to have LTR directionality, which means that in RTL UI
 // the elided filename is wrapped with LRE (Left-To-Right Embedding) mark and
 // PDF (Pop Directional Formatting) mark.
 UI_EXPORT string16 ElideFilename(const FilePath& filename,
                                  const gfx::Font& font,
                                  int available_pixel_width);
@@ skipping 63 matching lines @@
 // Truncates the string to length characters. This breaks the string at
 // the first word break before length, adding the horizontal ellipsis
 // character (unicode character 0x2026) to render ...
 // The supplied string is returned if the string has length characters or
 // less.
 UI_EXPORT string16 TruncateString(const string16& string, size_t length);
 
 }  // namespace ui
 
 #endif  // UI_BASE_TEXT_TEXT_ELIDER_H_