Label selection experiment

ui/gfx/render_text_harfbuzz.cc

 // 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.
 
 #include "ui/gfx/render_text_harfbuzz.h"
 
 #include <limits>
 #include <set>
 
 #include "base/i18n/bidi_line_iterator.h"
@@ skipping 827 matching lines @@
     }
     if (offset < end) {
       return SelectionModel(DisplayIndexToTextIndex(
           run.glyph_to_char[i] + (run.is_rtl ? 0 : 1)),
           (run.is_rtl ? CURSOR_FORWARD : CURSOR_BACKWARD));
     }
   }
   return EdgeSelectionModel(CURSOR_RIGHT);
 }
 
+bool RenderTextHarfBuzz::IsSelectionSupported() const {
+  // Todo(karandeepb): Support multi-line text selection.
+  return !multiline();
+}
+
 std::vector<RenderText::FontSpan> RenderTextHarfBuzz::GetFontSpansForTesting() {
   EnsureLayout();
 
   internal::TextRunList* run_list = GetRunList();
   std::vector<RenderText::FontSpan> spans;
   for (auto* run : run_list->runs()) {
     spans.push_back(RenderText::FontSpan(
         run->font, Range(DisplayIndexToTextIndex(run->range.start()),
                          DisplayIndexToTextIndex(run->range.end()))));
   }
@@ skipping 763 matching lines @@
 
       attribute.strike = run.strike;
       attribute.diagonal_strike = run.diagonal_strike;
       decorated_text->attributes.push_back(attribute);
     }
   }
   return true;
 }
 
 }  // namespace gfx