[Android] Implement the feature about visited link.

This patch is to implement the feature about visited link.
"a:visited" does not work when the url was clicked, so this feature
should be implemented.
Most of the code was ported from android webview.

BUG=https://crosswalk-project.org/jira/browse/XWALK-986
Merge pull request #1682 from wuhengzhi/visited_link_color

[Android] Implement the feature about visited link.