bug 742832 -  Add support for tab sharing for getUserMedia r=jesup

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extra : rebase_source : e42fbab31083b0e91be9992b2ba0062d14294c25
bug 890985 - crash in nsStandardURL::SetSpec @ nsStandardURL::BuildNormalizedSpec r=glandium

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extra : rebase_source : f5e45ed940e6311b20ba6d236b7153a5acb633b2