Bug 886528: Postpone popup menu initialization. [r=mfinkle]

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extra : rebase_source : 063c64a6340b92a75d00b1a5ed434b0a249827d6
Bug 886528: Move onCreatePanelView to GeckoApp. [r=mfinkle]

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extra : rebase_source : 4383294087f67382e8f96e9351f41ce6a61b7cf8