Add view port to runner for supporting mobile device.

[xiuqijix]

This change is 

[hoppipolla-critic-bot]

Critic review: https://critic.hoppipolla.co.uk/r/5774

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[jgraham]

What's the status here? I think it would be OK to merge only the <meta name=viewport> part of the patch.

[yugang]

@jgraham , the first two commits have the same reason here: #31, we just need merge the last one of the three commits.

[xiuqijix]

@jgraham , the first two commits have the same reason here: #31 .You can merge #32 after #31 , thanks.