Gmail webpage couldn't display well

Bug detailed description:
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In current image,if type http://mail.google.com and register in it,we could see that the checkbox which in the middle and on the left of pentacle seems too big,so we couldn't see the right side of it.

Reproduce steps:
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(1) Launch midbrowser
(2) type http://mail.google.com
(3) Register in it.

Current result:
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The checkbox in the middle couldn't fully display.

Expected result:
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The checkbox in the middle should display as same as firefox in windows and Linux.

Basic root-causing log:
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