MacViews: Enable word lookup for selectable views::Labels and multi-line text.

ui/gfx/render_text.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_RENDER_TEXT_H_
 #define UI_GFX_RENDER_TEXT_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 664 matching lines @@
 
   // Convert an index in |text_| to the index in |given_text|. The
   // |given_text| should be either |display_text_| or |layout_text_|
   // depending on the elide state.
   size_t TextIndexToGivenTextIndex(const base::string16& given_text,
                                    size_t index) const;
 
   // Adjust ranged styles to accommodate a new text length.
   void UpdateStyleLengths();
 
+  // Returns the line index for the given argument. |text_y| is relative to
+  // the text bounds. Returns -1 if |text_y| is above the text and
+  // lines().size() if |text_y| is below it.
+  int GetLineContainingYCoord(float text_y);
+
   // A convenience function to check whether the glyph attached to the caret
   // is within the given range.
   static bool RangeContainsCaret(const Range& range,
                                  size_t caret_pos,
                                  LogicalCursorDirection caret_affinity);
 
  private:
   friend class test::RenderTextTestApi;
 
   // Set the cursor to |position|, with the caret trailing the previous
@@ skipping 175 matching lines @@
   // Lines computed by EnsureLayout. These should be invalidated upon
   // OnLayoutTextAttributeChanged and OnDisplayTextAttributeChanged calls.
   std::vector<internal::Line> lines_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderText);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_RENDER_TEXT_H_