Bug 912340 - Add the manifest's 'role' property to mozIApplication. r=fabrice

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extra : rebase_source : 1b816681777578222c30d0184a865cf68e2c8efb
Bumping gaia.json for 2 gaia-central revision(s)

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https://hg.mozilla.org/integration/gaia-central/rev/f3513ac2018b
Author: gasolin <gasolin@gmail.com>
Desc: Merge pull request #12051 from gasolin/issue-911689

Bug 911689 - create tablet device distribution directory, r=timdream

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https://hg.mozilla.org/integration/gaia-central/rev/93a476764983
Author: gasolin <gasolin@gmail.com>
Desc: Bug 911689 - create tablet device distribution directory