[OpenJDK 2D-Dev] [9] Review Request: JDK-8029250 [macosx] There is no tray icon shown in the system tray area when case starts

[Petr Pchelko]

Hello, AWT and 2D teams.

Please review the fix for the issue:
https://bugs.openjdk.java.net/browse/JDK-8029250
It also resolves the issue:
https://bugs.openjdk.java.net/browse/JDK-6740321
The fix is available at:
http://cr.openjdk.java.net/~pchelko/9/8029250/webrev/

The problem:
In AWT we use a MediaTracker to wait for the tray icon loading. However, if the TrayIcon is an animated gif the following happen:
The MediaTracker installs an ImageObserver to an image and starts loading. After the first frame is loaded (and it's really all we need)
the media tracker correctly exits and removes it's ImageObserver. And as it's the only observer the checkConsumption is called in an 
ImageRepresentation. As the availinfo is just FRAMEBITS the successfully loaded frame was immediately disposed and AWT failed 
to draw a tray icon.

With best regards. Petr.