Bug 899492 - Disable plugin crash test when crashreporter not available. r=ted

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extra : rebase_source : abfb42265477940a373891241f6fa5d68e441e03
Bug 899504 - Disable about:memory vsize test under ASan. r=ted

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extra : rebase_source : be8f7dad036016dac89f4d3b78f7ff1e3c79d0a9