Reporting a more accurate buffered time for the video tag

Instead of showing that the entire file is buffered when the video first loads, this uses current time, current bytes, and buffered bytes to estimate buffered time.

Reviewed: http://codereview.chromium.org/2085012/
Submitted for: vrk@chromium.org
BUG=42285
TEST=NONE

Review URL: http://codereview.chromium.org/2192001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@48199 0039d316-1c4b-4281-b951-d872f2087c98
10 files changed