There are two Tracker.java files:
1. sun/tools/hprof/Tracker.java
2. com/sun/demo/jvmti/hprof/Tracker.java

As result there are 3 Tracker.class files in JDK:

1. jar -tf jre/lib/rt.jar |grep hprof
  com/sun/demo/jvmti/hprof/Tracker.class
  sun/tools/hprof/Tracker.class

2. jar -tf lib/tools.jar |grep hprof
  sun/tools/hprof/Tracker.class

According to src/share/demo/jvmti/hprof/hprof_tracker.h
com/sun/demo/jvmti/hprof/Tracker.java is actually used.

# cat src/share/demo/jvmti/hprof/hprof_tracker.h
   46 #define TRACKER_PACKAGE "com/sun/demo/jvmti/hprof"
   47 #define TRACKER_CLASS_NAME TRACKER_PACKAGE "/Tracker"

-katya

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The sun/tools one is a bug, it should have been removed but was left in
during a transition. There should only be one, in rt.jar.

-kto