Make Windows accessibility event firing aware of guest / child frames.

content/browser/frame_host/frame_accessibility.h

 // Copyright 2014 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.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_FRAME_ACCESSIBILITY_H_
 #define CONTENT_BROWSER_FRAME_HOST_FRAME_ACCESSIBILITY_H_
 
 #include <vector>
 
 #include "base/basictypes.h"
@@ skipping 30 matching lines @@
   void OnRenderFrameHostDestroyed(RenderFrameHostImpl* render_frame_host);
 
   // Given a parent RenderFrameHostImpl and an accessibility node id, look up
   // a child frame or guest frame that was previously associated with this
   // frame and node id. If a mapping exists, return the resulting frame if
   // it's valid. If it doesn't resolve to a valid RenderFrameHostImpl,
   // returns NULL.
   RenderFrameHostImpl* GetChild(RenderFrameHostImpl* parent_frame_host,
                                 int accessibility_node_id);
 
+  // Given a parent RenderFrameHostImpl and an accessibility node id, look up
+  // all child frames or guest frames that were previously associated with this
+  // frame, and populate |child_frame_hosts| with all of them that resolve
+  // to a valid RenderFrameHostImpl.
+  void GetAllChildFrames(RenderFrameHostImpl* parent_frame_host,
+                         std::vector<RenderFrameHostImpl*>* child_frame_hosts);
+
   // Given a RenderFrameHostImpl, check the mapping table to see if it's
   // the child of a node in some other frame. If so, return true and
   // set the parent frame and accessibility node id in the parent frame,
   // otherwise return false.
   bool GetParent(RenderFrameHostImpl* child_frame_host,
                  RenderFrameHostImpl** out_parent_frame_host,
                  int* out_accessibility_node_id);
 
  private:
   FrameAccessibility();
   virtual ~FrameAccessibility();
 
+  RenderFrameHostImpl* GetRFHIFromFrameTreeNodeId(
+      RenderFrameHostImpl* parent_frame_host,
+      int64 child_frame_tree_node_id);
+
+  // This structure stores the parent-child relationship between an
+  // accessibility node in a parent frame and its child frame, where the
+  // child frame may be an iframe or the main frame of a guest browser
+  // plugin. It allows the accessibility code to walk both down and up
+  // the "composed" accessibility tree.
   struct ChildFrameMapping {
     ChildFrameMapping();
 
+    // The parent frame host. Required.
     RenderFrameHostImpl* parent_frame_host;
+
+    // The id of the accessibility node that's the host of the child frame,
+    // for example the accessibility node for the <iframe> element or the
+    // <embed> element.
     int accessibility_node_id;
+
+    // If the child frame is an iframe, this is the iframe's FrameTreeNode id,
+    // otherwise 0.
     int64 child_frame_tree_node_id;
+
+    // If the child frame is a browser plugin, this is its instance id,
+    // otherwise 0.
     int browser_plugin_instance_id;
   };
 
   std::vector<ChildFrameMapping> mappings_;
 
   friend struct DefaultSingletonTraits<FrameAccessibility>;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_FRAME_ACCESSIBILITY_H_