Reland: Use labels to display views tab titles.

ui/gfx/text_constants.h

 // 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.
 
 #ifndef UI_GFX_TEXT_CONSTANTS_H_
 #define UI_GFX_TEXT_CONSTANTS_H_
 
 namespace gfx {
 
 // TODO(msw): Distinguish between logical character stops and glyph stops?
 // TODO(msw): Merge with base::i18n::BreakIterator::BreakType.
 enum BreakType {
   CHARACTER_BREAK = 0, // Stop cursor movement on neighboring characters.
   WORD_BREAK,          // Stop cursor movement on nearest word boundaries.
   LINE_BREAK,          // Stop cursor movement on line ends as shown on screen.
 };
 
 // Horizontal text alignment modes.
 enum HorizontalAlignment {
   ALIGN_LEFT = 0, // Align the text's left edge with that of its display area.
   ALIGN_CENTER,   // Align the text's center with that of its display area.
   ALIGN_RIGHT,    // Align the text's right edge with that of its display area.
+  ALIGN_TO_HEAD,  // Align the text to its first strong character's direction.
 };
 
 // The directionality modes used to determine the base text direction.
 enum DirectionalityMode {
   DIRECTIONALITY_FROM_TEXT = 0, // Use the first strong character's direction.
   DIRECTIONALITY_FROM_UI,       // Use the UI locale's text reading direction.
   DIRECTIONALITY_FORCE_LTR,     // Use LTR regardless of content or UI locale.
   DIRECTIONALITY_FORCE_RTL,     // Use RTL regardless of content or UI locale.
 };
 
@@ skipping 14 matching lines @@
   ELIDE_HEAD,   // Add an ellipsis at the start of the string.
   ELIDE_MIDDLE, // Add an ellipsis in the middle of the string.
   ELIDE_TAIL,   // Add an ellipsis at the end of the string.
   ELIDE_EMAIL,  // Add ellipses to username and domain substrings.
   FADE_TAIL,    // Fade the string's end opposite of its horizontal alignment.
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_TEXT_CONSTANTS_H_