Use text affinity to return correct accessible line boundaries.

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 4355 matching lines @@
   }
   NOTREACHED();
   return ui::CHAR_BOUNDARY;
 }
 
 LONG BrowserAccessibilityWin::FindBoundary(
     const base::string16& text,
     IA2TextBoundaryType ia2_boundary,
     LONG start_offset,
     ui::TextBoundaryDirection direction) {
+  // If the boundary is relative to the caret, use the selection
+  // affinity, otherwise default to downstream affinity.
+  ui::AXTextAffinity affinity =
+      start_offset == IA2_TEXT_OFFSET_CARET ?
+      manager()->GetTreeData().sel_focus_affinity :
+      ui::AX_TEXT_AFFINITY_DOWNSTREAM;
+
   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);
+  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);
+      text, line_breaks, 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 796 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