One accessibility tree per frame.

content/browser/accessibility/browser_accessibility_manager_android.cc

Index: content/browser/accessibility/browser_accessibility_manager_android.cc
diff --git a/content/browser/accessibility/browser_accessibility_manager_android.cc b/content/browser/accessibility/browser_accessibility_manager_android.cc
index e527963e62cb2bf20f10ed054b6f39fd54cbd3aa..bfa6e2169bef30dca76b080c5f81027eb00bbb99 100644
--- a/content/browser/accessibility/browser_accessibility_manager_android.cc
+++ b/content/browser/accessibility/browser_accessibility_manager_android.cc
@@ -146,7 +146,7 @@ BrowserAccessibilityManagerAndroid::BrowserAccessibilityManagerAndroid(
 
 BrowserAccessibilityManagerAndroid::~BrowserAccessibilityManagerAndroid() {
   JNIEnv* env = AttachCurrentThread();
-  ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
+  ScopedJavaLocalRef<jobject> obj = GetJavaRefFromRootManager();
   if (obj.is_null())
     return;
 
@@ -182,7 +182,7 @@ void BrowserAccessibilityManagerAndroid::NotifyAccessibilityEvent(
     ui::AXEvent event_type,
     BrowserAccessibility* node) {
   JNIEnv* env = AttachCurrentThread();
-  ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
+  ScopedJavaLocalRef<jobject> obj = GetJavaRefFromRootManager();
   if (obj.is_null())
     return;
 
@@ -275,8 +275,8 @@ void BrowserAccessibilityManagerAndroid::OnLocationChanges(
   // nodes changed location, just send a single notification after a short
   // delay (to batch them), rather than lots of individual notifications.
   if (params.size() > 3) {
+    ScopedJavaLocalRef<jobject> obj = GetJavaRefFromRootManager();
     JNIEnv* env = AttachCurrentThread();
-    ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
     if (obj.is_null())
       return;
     Java_BrowserAccessibilityManager_sendDelayedWindowContentChangedEvent(
@@ -659,7 +659,7 @@ jboolean BrowserAccessibilityManagerAndroid::AdjustSlider(
 void BrowserAccessibilityManagerAndroid::HandleHoverEvent(
     BrowserAccessibility* node) {
   JNIEnv* env = AttachCurrentThread();
-  ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
+  ScopedJavaLocalRef<jobject> obj = GetJavaRefFromRootManager();
   if (obj.is_null())
     return;
 
@@ -896,9 +896,12 @@ void BrowserAccessibilityManagerAndroid::OnAtomicUpdateFinished(
     ui::AXTree* tree,
     bool root_changed,
     const std::vector<ui::AXTreeDelegate::Change>& changes) {
+  BrowserAccessibilityManager::OnAtomicUpdateFinished(
+      tree, root_changed, changes);
+
   if (root_changed) {
     JNIEnv* env = AttachCurrentThread();
-    ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
+    ScopedJavaLocalRef<jobject> obj = GetJavaRefFromRootManager();
     if (obj.is_null())
       return;
 
@@ -918,6 +921,18 @@ BrowserAccessibilityManagerAndroid::GetFromUniqueID(int32_t unique_id) {
       BrowserAccessibility::GetFromUniqueID(unique_id));
 }
 
+ScopedJavaLocalRef<jobject>
+BrowserAccessibilityManagerAndroid::GetJavaRefFromRootManager() {
+  BrowserAccessibilityManagerAndroid* root_manager =
+      static_cast<BrowserAccessibilityManagerAndroid*>(
+          GetRootManager());
+  if (!root_manager)
+    return ScopedJavaLocalRef<jobject>();
+
+  JNIEnv* env = AttachCurrentThread();
+  return root_manager->java_ref().get(env);
+}
+
 bool RegisterBrowserAccessibilityManager(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }