Correctly finds line boundaries in objects with rich text on Windows.

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 385 matching lines @@
     if (parent.isNull() || parent.language() != src.language())
       dst->AddStringAttribute(ui::AX_ATTR_LANGUAGE, src.language().utf8());
   }
 
   if (src.keyboardShortcut().length()) {
     dst->AddStringAttribute(
         ui::AX_ATTR_SHORTCUT,
         src.keyboardShortcut().utf8());
   }
 
+  if (dst->role == ui::AX_ROLE_STATIC_TEXT ||

[dmazzoni, 2016/04/22 21:43:38]

It wasn't my intent for "next on line" and "previous on line" to only be
supported for those roles. I think it can be quite helpful for other roles too.

As an example, suppose you have an inline image:

<p>Before <img src="graphic.png" alt="graphic"> After</p>

You should be able to use nextOnLine and previousOnLine to trace from the word
Before to the inline image, to the word After, if they all happen to be laid out
on the same line.

+      dst->role == ui::AX_ROLE_LINE_BREAK ||
+      dst->role == ui::AX_ROLE_INLINE_TEXT_BOX) {
+    if (!src.nextOnLine().isDetached())
+      dst->AddIntAttribute(ui::AX_ATTR_NEXT_ON_LINE_ID,
+                           src.nextOnLine().axID());
+
+    if (!src.previousOnLine().isDetached()) {
+      dst->AddIntAttribute(ui::AX_ATTR_PREVIOUS_ON_LINE_ID,
+                           src.previousOnLine().axID());
+    }
+  }
+
   if (!src.ariaActiveDescendant().isDetached()) {
     dst->AddIntAttribute(ui::AX_ATTR_ACTIVEDESCENDANT_ID,
                          src.ariaActiveDescendant().axID());
   }
 
   if (!src.url().isEmpty())
     dst->AddStringAttribute(ui::AX_ATTR_URL, src.url().string().utf8());
 
   if (dst->role == ui::AX_ROLE_HEADING)
     dst->AddIntAttribute(ui::AX_ATTR_HIERARCHICAL_LEVEL, src.headingLevel());
@@ skipping 224 matching lines @@
   }
 }
 
 blink::WebDocument BlinkAXTreeSource::GetMainDocument() const {
   if (render_frame_ && render_frame_->GetWebFrame())
     return render_frame_->GetWebFrame()->document();
   return WebDocument();
 }
 
 }  // namespace content