[7u12] Request for approval for 7177111 - Jcomponent.AccessibleJComponent.AddPropertyListeners adds exponential listeners

[Pete Brunet]

This is a request to push the following to 7u12:

7177111 - Jcomponent.AccessibleJComponent.AddPropertyListeners adds
exponential listeners.
http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7177111

Problem
When an AT (Assistive Technology, such as a screen reader) accesses a
Java application with several nested frames, too many property change
listeners are added resulting in a severe performance impact for an AT user.
 
The issue is due to the fact that there is an accessibleContainerHandler
field in both javax.swing.JComponent.AccessibleJComponent and its
superclass, java.awt.Container.AccessibleAWTContainer.  When an AT calls
JComponent.AccessibleJComponent.addPropertyChangeListener a handler is
new'd and assigned to its accessibleContainerHandler field and then the
same method in the superclass is called and it also new's and assigns a
handler to its accessibleContainerHandler field.  Since there are two
handlers, when a child component is later added there are two callbacks
and for each one the AT will call addPropertyChangeListener, each of
which will add two handlers.  For deeply nested trees the explosion of
events has a negative impact on performance, i.e. there are 2 handlers
added for the first level, 4 for the second level, 8 for the third
level, etc.
 
Solution
Remove protected field
javax.swing.JComponent.AccessibleJComponent.accessibleContainerHandler. 
Instead, the protected field of the same name in
java.awt.Container.AWTAccessibleContainer will be used.

Notes:
- The same fix is also one of a set of fixes for 7179482 which will go
into 8.
- Both 7177111 and 7179482 have been reviewed and approved by Artem
Ananiev, Anthony Petrov, and Alexandr Scherbatiy.
- See the reviews at:
  -
http://mail.openjdk.java.net/pipermail/swing-dev/2012-November/002332.html
  - http://mail.openjdk.java.net/pipermail/awt-dev/2012-November/003829.html
- See the code change at:
http://cr.openjdk.java.net/~ptbrunet/7177111/webrev.03/
- It has been determined that this fix will not cause a binary
incompatibility.

Thank you,
Pete