Mac DumpRenderTree's installSignalHandlers() is unreachable code
https://bugs.webkit.org/show_bug.cgi?id=107383

Reviewed by Sam Weinig.

The CrashHandler of DumpRenderTree were originally used for restoring
the color profile of the main display even if DRT crashes.

That feature was later limited to pixel tests only in r29999.

In r104351, the DRT was changed to use device color space. Making the crash
handlers useless, but they were left in the code since the error reporting
code was still reachable.

Later, r124581 refactored the code and dumpPixelsForCurrentTest
is being used before being assigned its value.
This did cause any regression because the code had become useless with the previous change.

* DumpRenderTree/mac/DumpRenderTree.mm:
Remove crashHandler() and installSignalHandlers() as they have become useless and
have been unreachable code for 6 months.
(dumpRenderTree):
Remove the code that was unreachable due to dumpPixelsForCurrentTest being always false
at those points.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140361 268f45cc-cd09-0410-ab3c-d52691b4dbfc