Get rid of AX_LINE_BREAKS attribute to improve performance.

content/browser/accessibility/browser_accessibility_win.cc

 // 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.
 
 #include "content/browser/accessibility/browser_accessibility_win.h"
 
 #include <UIAutomationClient.h>
 #include <UIAutomationCoreApi.h>
 
 #include <algorithm>
@@ skipping 4702 matching lines @@
 
   HandleSpecialTextOffset(text, &start_offset);
   if (ia2_boundary == IA2_TEXT_BOUNDARY_WORD)
     return GetWordStartBoundary(static_cast<int>(start_offset), direction);
   if (ia2_boundary == IA2_TEXT_BOUNDARY_LINE) {
     return GetLineStartBoundary(
         static_cast<int>(start_offset), direction, affinity);
   }
 
   ui::TextBoundaryType boundary = IA2TextBoundaryToTextBoundary(ia2_boundary);
-  const std::vector<int32_t>& line_breaks =
-      GetIntListAttribute(ui::AX_ATTR_LINE_BREAKS);
-  return ui::FindAccessibleTextBoundary(
-      text, line_breaks, boundary, start_offset, direction, affinity);
+  return ui::FindAccessibleTextBoundary(text, GetLineStartOffsets(), boundary,
+                                        start_offset, direction, affinity);
 }
 
 LONG BrowserAccessibilityWin::FindStartOfStyle(
     LONG start_offset,
     ui::TextBoundaryDirection direction) const {
   LONG text_length = static_cast<LONG>(GetText().length());
   DCHECK_GE(start_offset, 0);
   DCHECK_LE(start_offset, text_length);
 
   switch (direction) {
@@ skipping 802 matching lines @@
   return static_cast<BrowserAccessibilityWin*>(obj);
 }
 
 const BrowserAccessibilityWin*
 ToBrowserAccessibilityWin(const BrowserAccessibility* obj) {
   DCHECK(!obj || obj->IsNative());
   return static_cast<const BrowserAccessibilityWin*>(obj);
 }
 
 }  // namespace content