fixed #2280 Fixed video memory bug for WebGL removing texture
fixed #2280 Fixed video memory bug for WebGL removing texture
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-html5 into Iss2280_FixVideoMomeryBug
Merge pull request #975 from dingpinglv/Iss2280_FixVideoMomeryBug

fixed #2280 Fixed video memory bug for WebGL removing texture