Use text affinity to return correct accessible line boundaries.

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 132 matching lines @@
   tree_data->mimetype = document.isXHTMLDocument() ? "text/xhtml" : "text/html";
   tree_data->title = document.title().utf8();
   tree_data->url = document.url().string().utf8();
 
   WebAXObject focus = document.focusedAccessibilityObject();
   if (!focus.isNull())
     tree_data->focus_id = focus.axID();
 
   WebAXObject anchor_object, focus_object;
   int anchor_offset, focus_offset;
-  root.selection(anchor_object, anchor_offset, focus_object, focus_offset);
+  blink::WebAXTextAffinity anchor_affinity, focus_affinity;
+  root.selection(anchor_object, anchor_offset, anchor_affinity,
+                 focus_object, focus_offset, focus_affinity);
   if (!anchor_object.isNull() && !focus_object.isNull() &&
       anchor_offset >= 0 && focus_offset >= 0) {
     int32_t anchor_id = anchor_object.axID();
     int32_t focus_id = focus_object.axID();
     tree_data->sel_anchor_object_id = anchor_id;
     tree_data->sel_anchor_offset = anchor_offset;
     tree_data->sel_focus_object_id = focus_id;
     tree_data->sel_focus_offset = focus_offset;
+    tree_data->sel_anchor_affinity = AXTextAffinityFromBlink(anchor_affinity);
+    tree_data->sel_focus_affinity = AXTextAffinityFromBlink(focus_affinity);
   }
 
   // Get the tree ID for this frame and the parent frame.
   WebLocalFrame* web_frame = document.frame();
   if (web_frame) {
     RenderFrame* render_frame = RenderFrame::FromWebFrame(web_frame);
     tree_data->routing_id = render_frame->GetRoutingID();
 
     // Get the tree ID for the parent frame.
     blink::WebFrame* parent_web_frame = web_frame->parent();
@@ skipping 512 matching lines @@
   }
 }
 
 blink::WebDocument BlinkAXTreeSource::GetMainDocument() const {
   if (render_frame_ && render_frame_->GetWebFrame())
     return render_frame_->GetWebFrame()->document();
   return WebDocument();
 }
 
 }  // namespace content