Use text affinity to return correct accessible line boundaries.

components/test_runner/web_ax_object_proxy.cc

Index: components/test_runner/web_ax_object_proxy.cc
diff --git a/components/test_runner/web_ax_object_proxy.cc b/components/test_runner/web_ax_object_proxy.cc
index 1e3de2563968680d7a3af6a0e8e3fd6e3b93531e..be5d6111cf4d80fee5c69b74233cca6280f5e7fc 100644
--- a/components/test_runner/web_ax_object_proxy.cc
+++ b/components/test_runner/web_ax_object_proxy.cc
@@ -535,10 +535,14 @@ WebAXObjectProxy::GetObjectTemplateBuilder(v8::Isolate* isolate) {
                    &WebAXObjectProxy::SelectionAnchorObject)
       .SetProperty("selectionAnchorOffset",
                    &WebAXObjectProxy::SelectionAnchorOffset)
+      .SetProperty("selectionAnchorAffinity",
+                   &WebAXObjectProxy::SelectionAnchorAffinity)
       .SetProperty("selectionFocusObject",
                    &WebAXObjectProxy::SelectionFocusObject)
       .SetProperty("selectionFocusOffset",
                    &WebAXObjectProxy::SelectionFocusOffset)
+      .SetProperty("selectionFocusAffinity",
+                   &WebAXObjectProxy::SelectionFocusAffinity)
       .SetProperty("selectionStart", &WebAXObjectProxy::SelectionStart)
       .SetProperty("selectionEnd", &WebAXObjectProxy::SelectionEnd)
       .SetProperty("selectionStartLineNumber",
@@ -788,10 +792,12 @@ v8::Local<v8::Value> WebAXObjectProxy::SelectionAnchorObject() {
 
   blink::WebAXObject anchorObject;
   int anchorOffset = -1;
+  blink::WebAXTextAffinity anchorAffinity;
   blink::WebAXObject focusObject;
   int focusOffset = -1;
-  accessibility_object_.selection(anchorObject, anchorOffset,
-                                  focusObject, focusOffset);
+  blink::WebAXTextAffinity focusAffinity;
+  accessibility_object_.selection(anchorObject, anchorOffset, anchorAffinity,
+                                  focusObject, focusOffset, focusAffinity);
   if (anchorObject.isNull())
     return v8::Null(blink::mainThreadIsolate());
 
@@ -803,25 +809,44 @@ int WebAXObjectProxy::SelectionAnchorOffset() {
 
   blink::WebAXObject anchorObject;
   int anchorOffset = -1;
+  blink::WebAXTextAffinity anchorAffinity;
   blink::WebAXObject focusObject;
   int focusOffset = -1;
-  accessibility_object_.selection(anchorObject, anchorOffset,
-                                  focusObject, focusOffset);
+  blink::WebAXTextAffinity focusAffinity;
+  accessibility_object_.selection(anchorObject, anchorOffset, anchorAffinity,
+                                  focusObject, focusOffset, focusAffinity);
   if (anchorOffset < 0)
     return -1;
 
   return anchorOffset;
 }
 
+std::string WebAXObjectProxy::SelectionAnchorAffinity() {
+  accessibility_object_.updateLayoutAndCheckValidity();
+
+  blink::WebAXObject anchorObject;
+  int anchorOffset = -1;
+  blink::WebAXTextAffinity anchorAffinity;
+  blink::WebAXObject focusObject;
+  int focusOffset = -1;
+  blink::WebAXTextAffinity focusAffinity;
+  accessibility_object_.selection(anchorObject, anchorOffset, anchorAffinity,
+                                  focusObject, focusOffset, focusAffinity);
+  return anchorAffinity == blink::WebAXTextAffinityUpstream ?
+      "upstream" : "downstream";
+}
+
 v8::Local<v8::Value> WebAXObjectProxy::SelectionFocusObject() {
   accessibility_object_.updateLayoutAndCheckValidity();
 
   blink::WebAXObject anchorObject;
   int anchorOffset = -1;
+  blink::WebAXTextAffinity anchorAffinity;
   blink::WebAXObject focusObject;
   int focusOffset = -1;
-  accessibility_object_.selection(anchorObject, anchorOffset,
-                                  focusObject, focusOffset);
+  blink::WebAXTextAffinity focusAffinity;
+  accessibility_object_.selection(anchorObject, anchorOffset, anchorAffinity,
+                                  focusObject, focusOffset, focusAffinity);
   if (focusObject.isNull())
     return v8::Null(blink::mainThreadIsolate());
 
@@ -833,16 +858,33 @@ int WebAXObjectProxy::SelectionFocusOffset() {
 
   blink::WebAXObject anchorObject;
   int anchorOffset = -1;
+  blink::WebAXTextAffinity anchorAffinity;
   blink::WebAXObject focusObject;
   int focusOffset = -1;
-  accessibility_object_.selection(anchorObject, anchorOffset,
-                                  focusObject, focusOffset);
+  blink::WebAXTextAffinity focusAffinity;
+  accessibility_object_.selection(anchorObject, anchorOffset, anchorAffinity,
+                                  focusObject, focusOffset, focusAffinity);
   if (focusOffset < 0)
     return -1;
 
   return focusOffset;
 }
 
+std::string WebAXObjectProxy::SelectionFocusAffinity() {
+  accessibility_object_.updateLayoutAndCheckValidity();
+
+  blink::WebAXObject anchorObject;
+  int anchorOffset = -1;
+  blink::WebAXTextAffinity anchorAffinity;
+  blink::WebAXObject focusObject;
+  int focusOffset = -1;
+  blink::WebAXTextAffinity focusAffinity;
+  accessibility_object_.selection(anchorObject, anchorOffset, anchorAffinity,
+                                  focusObject, focusOffset, focusAffinity);
+  return focusAffinity == blink::WebAXTextAffinityUpstream ?
+      "upstream" : "downstream";
+}
+
 int WebAXObjectProxy::SelectionStart() {
   accessibility_object_.updateLayoutAndCheckValidity();
   return accessibility_object_.selectionStart();