Add a histogram for SpdyConnectionLatency.
Add a histogram for SpdyConnectionLatency.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/543040

git-svn-id: http://src.chromium.org/svn/trunk/src@36189 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 46af957f74e70f33c9c9812824a4ea10b896f36a
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser