DevTools: Fix Document DOM Trees container distance to be 0.

BUG=
R=loislo@chromium.org

Review URL: https://codereview.chromium.org/17705002

git-svn-id: svn://svn.chromium.org/blink/trunk@153012 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Sources panel search sould always continue from the last cursor position.

Search always continues from the last cursor position now even if editor selection was changed after starting the search.
Search math index is now shown from the beginning of the file.

Review URL: https://chromiumcodereview.appspot.com/17692002

git-svn-id: svn://svn.chromium.org/blink/trunk@153013 bbb929c8-8fbe-4397-9dbb-9b2b20218538