WebSocket Pepper API: add a unit test for the bufferedAmount property

Add a unit test for the bufferedAmount property to verify its behaviors around
connection close.

BUG=87310
TEST=ui_test --gtest_filter='PPAPITest.WebSocket_BufferedAmount'

Review URL: http://codereview.chromium.org/8989047

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@117415 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed