Ensures detached subtrees have root nodes that retain the previous parent.

Also, removes ReplaceChild, which doesn't seem to be used anymore.
BUG=none
TEST=BrowserAccessibilityManagerTest.TestReuseBrowserAccessibilityObjects2
Review URL: http://codereview.chromium.org/6902038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@83072 0039d316-1c4b-4281-b951-d872f2087c98

6 files changed, 9 insertions, 26 deletions

diff --git a/chrome/browser/accessibility/browser_accessibility.cc b/chrome/browser/accessibility/browser_accessibility.cc
index 03a51e8..a54eb1e 100644
--- a/chrome/browser/accessibility/browser_accessibility.cc
+++ b/chrome/browser/accessibility/browser_accessibility.cc
@@ -32,14 +32,6 @@ BrowserAccessibility::BrowserAccessibility()
 BrowserAccessibility::~BrowserAccessibility() {
 }
 
-void BrowserAccessibility::ReplaceChild(
-    BrowserAccessibility* old_acc, BrowserAccessibility* new_acc) {
-  DCHECK_EQ(children_[old_acc->index_in_parent_], old_acc);
-
-  old_acc = children_[old_acc->index_in_parent_];
-  children_[old_acc->index_in_parent_] = new_acc;
-}
-
 void BrowserAccessibility::Initialize(
     BrowserAccessibilityManager* manager,
     BrowserAccessibility* parent,
diff --git a/chrome/browser/accessibility/browser_accessibility.h b/chrome/browser/accessibility/browser_accessibility.h
index 6f42911..9f28c27 100644
--- a/chrome/browser/accessibility/browser_accessibility.h
+++ b/chrome/browser/accessibility/browser_accessibility.h
@@ -48,11 +48,6 @@ class BrowserAccessibility {
   // have been reset with new values from the renderer process.
   virtual void Initialize();
 
-  // Replace a child object. Used when updating the accessibility tree.
-  virtual void ReplaceChild(
-      BrowserAccessibility* old_acc,
-      BrowserAccessibility* new_acc);
-
   // Initialize this object, reading attributes from |src|. Does not
   // recurse into children of |src| and build the whole subtree.
   void Initialize(BrowserAccessibilityManager* manager,
diff --git a/chrome/browser/accessibility/browser_accessibility_mac.h b/chrome/browser/accessibility/browser_accessibility_mac.h
index 2f8e04a..f3c6605 100644
--- a/chrome/browser/accessibility/browser_accessibility_mac.h
+++ b/chrome/browser/accessibility/browser_accessibility_mac.h
@@ -22,11 +22,6 @@ class BrowserAccessibilityMac : public BrowserAccessibility {
   virtual void NativeReleaseReference();
 
   // Overrides from BrowserAccessibility.
-  // Used to know when to update the cocoa children.
-  virtual void ReplaceChild(
-      BrowserAccessibility* old_acc,
-      BrowserAccessibility* new_acc);
-
   // The BrowserAccessibilityCocoa associated with us.
   BrowserAccessibilityCocoa* native_view() const {
     return browser_accessibility_cocoa_;
diff --git a/chrome/browser/accessibility/browser_accessibility_mac.mm b/chrome/browser/accessibility/browser_accessibility_mac.mm
index 97f016a..305e93c8 100644
--- a/chrome/browser/accessibility/browser_accessibility_mac.mm
+++ b/chrome/browser/accessibility/browser_accessibility_mac.mm
@@ -47,13 +47,6 @@ void BrowserAccessibilityMac::NativeReleaseReference() {
   }
 }
 
-void BrowserAccessibilityMac::ReplaceChild(
-      BrowserAccessibility* old_acc,
-      BrowserAccessibility* new_acc) {
-  BrowserAccessibility::ReplaceChild(old_acc, new_acc);
-  [browser_accessibility_cocoa_ childrenChanged];
-}
-
 BrowserAccessibilityCocoa* BrowserAccessibility::toBrowserAccessibilityCocoa() {
   return static_cast<BrowserAccessibilityMac*>(this)->
       native_view();
diff --git a/chrome/browser/accessibility/browser_accessibility_manager.cc b/chrome/browser/accessibility/browser_accessibility_manager.cc
index 3a12164..36cbfd2 100644
--- a/chrome/browser/accessibility/browser_accessibility_manager.cc
+++ b/chrome/browser/accessibility/browser_accessibility_manager.cc
@@ -282,6 +282,9 @@ BrowserAccessibility* BrowserAccessibilityManager::UpdateNode(
     return current;
   }
 
+  BrowserAccessibility* current_parent = current->parent();
+  int current_index_in_parent = current->index_in_parent();
+
   // Detach all of the nodes in the old tree and get a single flat vector
   // of all node pointers.
   std::vector<BrowserAccessibility*> old_tree_nodes;
@@ -289,7 +292,8 @@ BrowserAccessibility* BrowserAccessibilityManager::UpdateNode(
 
   // Build a new tree, reusing old nodes if possible. Each node that's
   // reused will have its reference count incremented by one.
-  current = CreateAccessibilityTree(NULL, src, -1);
+  current =
+      CreateAccessibilityTree(current_parent, src, current_index_in_parent);
 
   // Decrement the reference count of all nodes in the old tree, which will
   // delete any nodes no longer needed.
diff --git a/chrome/browser/accessibility/browser_accessibility_manager_unittest.cc b/chrome/browser/accessibility/browser_accessibility_manager_unittest.cc
index 1b6aa1a..4d8bb15 100644
--- a/chrome/browser/accessibility/browser_accessibility_manager_unittest.cc
+++ b/chrome/browser/accessibility/browser_accessibility_manager_unittest.cc
@@ -451,6 +451,10 @@ TEST(BrowserAccessibilityManagerTest, TestReuseBrowserAccessibilityObjects2) {
   EXPECT_TRUE(child2_accessible->instance_active());
   EXPECT_FALSE(child3_accessible->instance_active());
 
+  // Ensure that we retain the parent of the detached subtree.
+  EXPECT_EQ(root_accessible, container_accessible->parent());
+  EXPECT_EQ(0, container_accessible->index_in_parent());
+
   // Check that the index in parent has been updated.
   EXPECT_EQ(2, child2_accessible->index_in_parent());