Don't post events on internal nodes in the accessibility tree on Android.

content/browser/accessibility/browser_accessibility_manager_android.cc

 // Copyright 2013 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/browser/accessibility/browser_accessibility_manager_android.h"
 
 #include <stddef.h>
 
 #include <cmath>
 
@@ skipping 188 matching lines @@
 
 void BrowserAccessibilityManagerAndroid::NotifyAccessibilityEvent(
     BrowserAccessibilityEvent::Source source,
     ui::AXEvent event_type,
     BrowserAccessibility* node) {
   JNIEnv* env = AttachCurrentThread();
   ScopedJavaLocalRef<jobject> obj = GetJavaRefFromRootManager();
   if (obj.is_null())
     return;
 
-  BrowserAccessibilityAndroid* android_node =
-      static_cast<BrowserAccessibilityAndroid*>(node);
-
   if (event_type == ui::AX_EVENT_HIDE)
     return;
 
   if (event_type == ui::AX_EVENT_TREE_CHANGED)
     return;
 
   // Layout changes are handled in OnLocationChanges and
   // SendLocationChangeEvents.
   if (event_type == ui::AX_EVENT_LAYOUT_COMPLETE)
     return;
 
   if (event_type == ui::AX_EVENT_HOVER) {
     HandleHoverEvent(node);
     return;
   }
 
+  // Sometimes we get events on nodes in our internal accessibility tree
+  // that aren't exposed on Android. Walk up the ancestors and update |node|
+  // to point to the highest ancestor that's a leaf node.
+  BrowserAccessibility* parent = node->GetParent();
+  while (parent) {
+    if (parent->PlatformIsLeaf())
+      node = parent;

[David Tseng, 2016/10/04 19:56:15]

Break? Are there leaves that have ancestor leaves?

[dmazzoni, 2016/10/04 21:35:09]

In theory yes? I want this to behave as if you walked the tree.

+    parent = parent->GetParent();
+  }
+
   // Always send AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED to notify
   // the Android system that the accessibility hierarchy rooted at this
   // node has changed.
   Java_BrowserAccessibilityManager_handleContentChanged(env, obj,
                                                         node->unique_id());
 
   // Ignore load complete events on iframes.
   if (event_type == ui::AX_EVENT_LOAD_COMPLETE &&
       node->manager() != GetRootManager()) {
     return;
   }
 
+  BrowserAccessibilityAndroid* android_node =
+      static_cast<BrowserAccessibilityAndroid*>(node);
   switch (event_type) {
     case ui::AX_EVENT_LOAD_COMPLETE:
       Java_BrowserAccessibilityManager_handlePageLoaded(
           env, obj, GetFocus()->unique_id());
       break;
     case ui::AX_EVENT_FOCUS:
       Java_BrowserAccessibilityManager_handleFocusChanged(env, obj,
                                                           node->unique_id());
       break;
     case ui::AX_EVENT_CHECKED_STATE_CHANGED:
@@ skipping 693 matching lines @@
 
   JNIEnv* env = AttachCurrentThread();
   return root_manager->java_ref().get(env);
 }
 
 bool RegisterBrowserAccessibilityManager(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content