Initialize salt_ to zero in VisitedLinkCommon.
Initialize salt_ to zero in VisitedLinkCommon.

Previously, this memory would remain uninitialized until the renderer received
a VisitedLink_NewTable message.  This was causing valgrind errors in
PhishingDOMFeatureExtractorTest when WebKit computed URL fingerprints, since
the test never sends a VisitedLink_NewTable message.

BUG=none
TEST=no valgrind errors in PhishingDOMFeatureExtractorTest

Review URL: http://codereview.chromium.org/2873081

git-svn-id: http://src.chromium.org/svn/trunk/src@54376 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 45373f3778e077bbc6288f5e4ca3311f41b53f99
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