Fix handling of case where the same AccessibilityObject appears as a

child of more than one parent. Add some additional DCHECKs so that such
a problem would be caught even earlier if they were to reoccur.

BUG=75496
TEST=Addes new browser test CrossPlatformMultipleInheritanceAccessibility2

Review URL: http://codereview.chromium.org/6683010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@78025 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 12 insertions, 9 deletions

diff --git a/webkit/glue/webaccessibility.cc b/webkit/glue/webaccessibility.cc
index 48cc339..09a9212 100644
--- a/webkit/glue/webaccessibility.cc
+++ b/webkit/glue/webaccessibility.cc
@@ -395,10 +395,10 @@ void WebAccessibility::Init(const WebKit::WebAccessibilityObject& src,
 
       // Some nodes appear in the tree in more than one place: for example,
       // a cell in a table appears as a child of both a row and a column.
-      // Only recursively add child nodes that have this node as one of its
-      // ancestors. For child nodes that are actually parented to something
-      // else, store only the ID.
-      if (IsAncestorOf(src, child)) {
+      // Only recursively add child nodes that have this node as its
+      // unignored parent. For child nodes that are actually parented to
+      // somethinng else, store only the ID.
+      if (IsParentUnignoredOf(src, child)) {
         children.push_back(WebAccessibility(child, cache, include_children));
       } else {
         indirect_child_ids.push_back(cache->addOrGetId(child));
@@ -407,11 +407,11 @@ void WebAccessibility::Init(const WebKit::WebAccessibilityObject& src,
   }
 }
 
-bool WebAccessibility::IsAncestorOf(
+bool WebAccessibility::IsParentUnignoredOf(
     const WebKit::WebAccessibilityObject& ancestor,
     const WebKit::WebAccessibilityObject& child) {
   WebKit::WebAccessibilityObject parent = child.parentObject();
-  while (!parent.isNull() && !parent.equals(ancestor))
+  while (!parent.isNull() && parent.accessibilityIsIgnored())
     parent = parent.parentObject();
   return parent.equals(ancestor);
 }
diff --git a/webkit/glue/webaccessibility.h b/webkit/glue/webaccessibility.h
index b67ce83..85fe6d2 100644
--- a/webkit/glue/webaccessibility.h
+++ b/webkit/glue/webaccessibility.h
@@ -198,9 +198,12 @@ struct WebAccessibility {
             WebKit::WebAccessibilityCache* cache,
             bool include_children);
 
-  // Returns true if |ancestor| is an ancestor of |child|.
-  bool IsAncestorOf(const WebKit::WebAccessibilityObject& ancestor,
-                    const WebKit::WebAccessibilityObject& child);
+  // Returns true if |ancestor| is the first unignored parent of |child|,
+  // which means that when walking up the parent chain from |child|,
+  // |ancestor| is the *first* ancestor that isn't marked as
+  // accessibilityIsIgnored().
+  bool IsParentUnignoredOf(const WebKit::WebAccessibilityObject& ancestor,
+                           const WebKit::WebAccessibilityObject& child);
 
  public:
   // This is a simple serializable struct. All member variables should be