Can be disable with system property:
 "org.eclipse.jface.resource.cacheSize=0"
Default cacheSize=300.

Removes all hotspots from org.eclipse.jface.resource.ResourceManager

Does not only affect ResourceManager but allows also repeated calls of
setImage() to check for same Image instance and avoid that NO-OP.

Especially from loading images for toolbar:
The problem was that the former reference counting did destroy the
images just before reloading them again.

Caches all Images loaded from filesystem/url during startup of
org.eclipse.sdk.ide. Only the light weight RGBColorDescriptor is
destroyed during startup of org.eclipse.sdk.ide.

Change-Id: I5bfd38dce66ebcc062e140098316fda826e7bf5e
Signed-off-by: Joerg Kubitz <jkubitz-eclipse@gmx.de>
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.ui/+/186086
Tested-by: Platform Bot <platform-bot@eclipse.org>
Reviewed-by: Sebastian Zarnekow <sebastian.zarnekow@gmail.com>