Get rid of AX_LINE_BREAKS attribute to improve performance.

content/browser/accessibility/browser_accessibility.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.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 
@@ skipping 211 matching lines @@
   const BrowserAccessibility* leaf_object = PlatformDeepestLastChild();
   if (!leaf_object)
     leaf_object = this;
 
   int32_t next_on_line_id;
   if (leaf_object->GetIntAttribute(ui::AX_ATTR_NEXT_ON_LINE_ID,
                                    &next_on_line_id)) {
     const BrowserAccessibility* next_on_line =
         manager()->GetFromID(next_on_line_id);
     // In the case of a static text sibling, the object designated to be the
-    // next object on this line might be one of its children, i.e. the last
+    // next object on this line might be one of its children, i.e. the first
     // inline text box.
     return next_on_line && next_on_line->IsDescendantOf(next_sibling);
   }
   return false;
 }
 
 BrowserAccessibility* BrowserAccessibility::PlatformDeepestFirstChild() const {
   if (!PlatformChildCount())
     return nullptr;
 
@@ skipping 283 matching lines @@
 }
 
 int BrowserAccessibility::GetLineStartBoundary(
     int start,
     ui::TextBoundaryDirection direction,
     ui::AXTextAffinity affinity) const {
   DCHECK_GE(start, 0);
   DCHECK_LE(start, static_cast<int>(GetText().length()));
 
   if (IsSimpleTextControl()) {
-    const std::vector<int32_t>& line_breaks =
-        GetIntListAttribute(ui::AX_ATTR_LINE_BREAKS);
-    return ui::FindAccessibleTextBoundary(GetText(), line_breaks,
+    return ui::FindAccessibleTextBoundary(GetText(), GetLineStartOffsets(),
                                           ui::LINE_BOUNDARY, start, direction,
                                           affinity);
   }
 
   // Keeps track of the start offset of each consecutive line.
   int line_start = 0;
   // Keeps track of the length of each consecutive line.
   int line_length = 0;
   for (size_t i = 0; i < InternalChildCount(); ++i) {
     const BrowserAccessibility* child = InternalGetChild(i);
@@ skipping 586 matching lines @@
         if (!name.empty())
           name += " ";
         name += child_name;
       }
     }
   }
 
   return name;
 }
 
+std::vector<int> BrowserAccessibility::GetLineStartOffsets() const {
+  if (!instance_active())
+    return std::vector<int>();
+  return node()->GetOrComputeLineStartOffsets();
+}
+
 base::string16 BrowserAccessibility::GetInnerText() const {
   if (IsTextOnlyObject())
     return GetString16Attribute(ui::AX_ATTR_NAME);
 
   base::string16 text;
   for (size_t i = 0; i < InternalChildCount(); ++i)
     text += InternalGetChild(i)->GetInnerText();
   return text;
 }
 
@@ skipping 57 matching lines @@
       }
     }
 
     node = container;
   }
 
   return gfx::ToEnclosingRect(bounds);
 }
 
 }  // namespace content