Add swapBuffer call to SkGLContextHelper.

R=bsalomon@google.com

Review URL: https://codereview.chromium.org/26701002

git-svn-id: http://skia.googlecode.com/svn/trunk/include@11682 2bbb7eff-a529-9590-31e7-b0007b416f81
6 files changed