Bug 947802 (part 1) - Inline DumpReport().  r=mccr8.

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extra : rebase_source : f5c8a655e88dc7641c2a9971d1174b0d689bf3b4
Bug 947802 (part 2) - Replace enumerateReporters() with getReportsForThisProcess().  r=mccr8.

--HG--
extra : rebase_source : 1c70e838e3600745f69c5772a084398f78d4c477
Bug 697343 - Remove getElementIfPresent. r=Waldo
Bug 697343 - Introduce a slice hook to allow optimizing Array.prototype.slice for Proxies etc. r=jandem,bz
Bug 697343 - Add slice hook to DOM bindings like NodeList. r=peterv,bhackett
Bug 697343 - Add slice hook test. r=jandem