Migrate BrowserAccessibility windows unique id handling to AXPlatformNodeWin.

content/browser/accessibility/browser_accessibility.cc

Index: content/browser/accessibility/browser_accessibility.cc
diff --git a/content/browser/accessibility/browser_accessibility.cc b/content/browser/accessibility/browser_accessibility.cc
index 3824914ff94178face04b07104e45331ba0bf2a0..7d371493db9ea0060c4f56586a41701dbf73a13f 100644
--- a/content/browser/accessibility/browser_accessibility.cc
+++ b/content/browser/accessibility/browser_accessibility.cc
@@ -42,16 +42,16 @@ BrowserAccessibility::BrowserAccessibility()
     : manager_(nullptr),
       node_(nullptr),
       unique_id_(ui::GetNextAXPlatformNodeUniqueId()) {
-  g_unique_id_map.Get()[unique_id_] = this;
+  g_unique_id_map.Get()[unique_id()] = this;
 }
 
 BrowserAccessibility::~BrowserAccessibility() {
-  if (unique_id_)
-    g_unique_id_map.Get().erase(unique_id_);
+  if (unique_id())
+    g_unique_id_map.Get().erase(unique_id());
 }
 
 // static
-BrowserAccessibility* BrowserAccessibility::GetFromUniqueID(int32_t unique_id) {
+BrowserAccessibility* BrowserAccessibility::GetFromUniqueId(int32_t unique_id) {
   auto iter = g_unique_id_map.Get().find(unique_id);
   if (iter == g_unique_id_map.Get().end())
     return nullptr;
@@ -573,9 +573,8 @@ void BrowserAccessibility::Destroy() {
   node_ = NULL;
   manager_ = NULL;
 
-  if (unique_id_)
-    g_unique_id_map.Get().erase(unique_id_);
-  unique_id_ = 0;
+  if (unique_id())
+    g_unique_id_map.Get().erase(unique_id());
 
   NativeReleaseReference();
 }
@@ -584,6 +583,10 @@ void BrowserAccessibility::NativeReleaseReference() {
   delete this;
 }
 
+int32_t BrowserAccessibility::unique_id() const {
+  return unique_id_;
+}
+
 bool BrowserAccessibility::HasBoolAttribute(
     ui::AXBoolAttribute attribute) const {
   return GetData().HasBoolAttribute(attribute);