Bug 825105 - Fix two clang warnings in media/mtransport/.  r=ekr.

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extra : rebase_source : 5a1aa4960f364f50f12c1cee1f0838202be6191d
Bug 787017. Die more verbosely on Android during Layers init. r=bjacob

This might give us some more information on what's happening.

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extra : rebase_source : f2865e0d59746170d8b258334673acbd301dca54