Handled case when chrome.runtime isn't present, in Chrome 21 and ealier.

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extra : rebase_source : b075a873d7e37f6adeda82d9a4d934161e686118
Fixed properties defined on prototype in Safari background page proxy.

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extra : rebase_source : bfe7a263e3330bae685f6785689a57d1b017ab1e
Added missing ext/*.js includes to block.html.

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extra : rebase_source : 6af5583db619a33711a533aeb73a3a1f6f80bc20