Enables Activity Log to extract URLs from URL assignment
DOM API calls and place them into argUrl field of an
Activity Log entry.

BUG=339882

Review URL: https://codereview.chromium.org/160753002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251348 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251348