Make use of new faster Blink AX live region APIs.

content/renderer/accessibility/blink_ax_tree_source.cc

Index: content/renderer/accessibility/blink_ax_tree_source.cc
diff --git a/content/renderer/accessibility/blink_ax_tree_source.cc b/content/renderer/accessibility/blink_ax_tree_source.cc
index c2ca4ef477543a70210e16cff3f19ff754666ebe..51d753121b738a11b97a0be6cd895bdbfc46262a 100644
--- a/content/renderer/accessibility/blink_ax_tree_source.cc
+++ b/content/renderer/accessibility/blink_ax_tree_source.cc
@@ -60,10 +60,6 @@ bool IsParentUnignoredOf(WebAXObject ancestor,
   return parent.equals(ancestor);
 }
 
-bool IsTrue(std::string html_value) {
-  return LowerCaseEqualsASCII(html_value, "true");
-}
-
 std::string GetEquivalentAriaRoleString(const ui::AXRole role) {
   switch (role) {
     case ui::AX_ROLE_ARTICLE:
@@ -313,10 +309,6 @@ void BlinkAXTreeSource::SerializeNode(blink::WebAXObject src,
 
   WebNode node = src.node();
   bool is_iframe = false;
-  std::string live_atomic;
-  std::string live_busy;
-  std::string live_status;
-  std::string live_relevant;
 
   if (!node.isNull() && node.isElementNode()) {
     WebElement element = node.to<WebElement>();
@@ -371,12 +363,6 @@ void BlinkAXTreeSource::SerializeNode(blink::WebAXObject src,
         dst->AddStringAttribute(ui::AX_ATTR_ROLE, role);
     }
 
-    // Live region attributes
-    live_atomic = UTF16ToUTF8(element.getAttribute("aria-atomic"));
-    live_busy = UTF16ToUTF8(element.getAttribute("aria-busy"));
-    live_status = UTF16ToUTF8(element.getAttribute("aria-live"));
-    live_relevant = UTF16ToUTF8(element.getAttribute("aria-relevant"));
-
     // Browser plugin (used in a <webview>).
     if (node_to_browser_plugin_instance_id_map_) {
       BrowserPlugin* browser_plugin = BrowserPlugin::GetFromNode(element);
@@ -388,64 +374,21 @@ void BlinkAXTreeSource::SerializeNode(blink::WebAXObject src,
     }
   }
 
-  // Walk up the parent chain to set live region attributes of containers
-  std::string container_live_atomic;
-  std::string container_live_busy;
-  std::string container_live_status;
-  std::string container_live_relevant;
-  WebAXObject container_accessible = src;
-  while (!container_accessible.isDetached()) {
-    WebNode container_node = container_accessible.node();
-    if (!container_node.isNull() && container_node.isElementNode()) {
-      WebElement container_elem = container_node.to<WebElement>();
-      if (container_elem.hasAttribute("aria-atomic") &&
-          container_live_atomic.empty()) {
-        container_live_atomic =
-            UTF16ToUTF8(container_elem.getAttribute("aria-atomic"));
-      }
-      if (container_elem.hasAttribute("aria-busy") &&
-          container_live_busy.empty()) {
-        container_live_busy =
-            UTF16ToUTF8(container_elem.getAttribute("aria-busy"));
-      }
-      if (container_elem.hasAttribute("aria-live") &&
-          container_live_status.empty()) {
-        container_live_status =
-            UTF16ToUTF8(container_elem.getAttribute("aria-live"));
-      }
-      if (container_elem.hasAttribute("aria-relevant") &&
-          container_live_relevant.empty()) {
-        container_live_relevant =
-            UTF16ToUTF8(container_elem.getAttribute("aria-relevant"));
-      }
-    }
-    container_accessible = container_accessible.parentObject();
-  }
-
-  if (!live_atomic.empty())
-    dst->AddBoolAttribute(ui::AX_ATTR_LIVE_ATOMIC, IsTrue(live_atomic));
-  if (!live_busy.empty())
-    dst->AddBoolAttribute(ui::AX_ATTR_LIVE_BUSY, IsTrue(live_busy));
-  if (!live_status.empty())
-    dst->AddStringAttribute(ui::AX_ATTR_LIVE_STATUS, live_status);
-  if (!live_relevant.empty())
-    dst->AddStringAttribute(ui::AX_ATTR_LIVE_RELEVANT, live_relevant);
-
-  if (!container_live_atomic.empty()) {
+  if (src.isInLiveRegion()) {
+    dst->AddBoolAttribute(ui::AX_ATTR_LIVE_ATOMIC, src.liveRegionAtomic());
+    dst->AddBoolAttribute(ui::AX_ATTR_LIVE_BUSY, src.liveRegionBusy());
+    dst->AddStringAttribute(ui::AX_ATTR_LIVE_STATUS,
+                            UTF16ToUTF8(src.liveRegionStatus()));
+    dst->AddStringAttribute(ui::AX_ATTR_LIVE_RELEVANT,
+                            UTF16ToUTF8(src.liveRegionRelevant()));
     dst->AddBoolAttribute(ui::AX_ATTR_CONTAINER_LIVE_ATOMIC,
-                          IsTrue(container_live_atomic));
-  }
-  if (!container_live_busy.empty()) {
+                          src.containerLiveRegionAtomic());
     dst->AddBoolAttribute(ui::AX_ATTR_CONTAINER_LIVE_BUSY,
-                          IsTrue(container_live_busy));
-  }
-  if (!container_live_status.empty()) {
+                          src.containerLiveRegionBusy());
     dst->AddStringAttribute(ui::AX_ATTR_CONTAINER_LIVE_STATUS,
-                            container_live_status);
-  }
-  if (!container_live_relevant.empty()) {
+                            UTF16ToUTF8(src.containerLiveRegionStatus()));
     dst->AddStringAttribute(ui::AX_ATTR_CONTAINER_LIVE_RELEVANT,
-                            container_live_relevant);
+                            UTF16ToUTF8(src.containerLiveRegionRelevant()));
   }
 
   if (dst->role == ui::AX_ROLE_PROGRESS_INDICATOR ||