Get rid of AX_LINE_BREAKS attribute to improve performance.

content/renderer/accessibility/blink_ax_tree_source.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 "content/renderer/accessibility/blink_ax_tree_source.h"
 
 #include <stddef.h>
 
 #include <set>
 
@@ skipping 490 matching lines @@
     for (unsigned i = 0; i < element.attributeCount(); ++i) {
       std::string name = base::ToLowerASCII(
           element.attributeLocalName(i).utf8());
       std::string value = element.attributeValue(i).utf8();
       dst->html_attributes.push_back(std::make_pair(name, value));
     }
 
     if (src.isEditable()) {
       dst->AddIntAttribute(ui::AX_ATTR_TEXT_SEL_START, src.selectionStart());
       dst->AddIntAttribute(ui::AX_ATTR_TEXT_SEL_END, src.selectionEnd());
-
-      WebVector<int> src_line_breaks;
-      src.lineBreaks(src_line_breaks);
-      if (src_line_breaks.size()) {
-        std::vector<int32_t> line_breaks;
-        line_breaks.reserve(src_line_breaks.size());
-        for (size_t i = 0; i < src_line_breaks.size(); ++i)
-          line_breaks.push_back(src_line_breaks[i]);
-        dst->AddIntListAttribute(ui::AX_ATTR_LINE_BREAKS, line_breaks);
-      }
     }
 
     // ARIA role.
     if (element.hasAttribute("role")) {
       dst->AddStringAttribute(
           ui::AX_ATTR_ROLE,
           element.getAttribute("role").utf8());
     } else {
       std::string role = GetEquivalentAriaRoleString(dst->role);
       if (!role.empty())
@@ skipping 166 matching lines @@
   }
 }
 
 blink::WebDocument BlinkAXTreeSource::GetMainDocument() const {
   if (render_frame_ && render_frame_->GetWebFrame())
     return render_frame_->GetWebFrame()->document();
   return WebDocument();
 }
 
 }  // namespace content