Add a unit test for viewsource reverse

Add a unit test for viewsource reverse writer handler

The reverse writer for viewsource had an incorrect assumption about the path component of URL which was causing a duplication of query and fragment parameters. This change is to unit test the fix that  went in
https://codereview.chromium.org/655023002/

BUG=336846
Committed: https://crrev.com/d8e1571cb9fc788aedca3358e8370616fe5991ca
Cr-Commit-Position: refs/heads/master@{#300281}

[sgurun-gerrit only, 2014-10-17 15:08:25]

sgurun@chromium.org changed reviewers:
+ sky@chromium.org

[sgurun-gerrit only, 2014-10-17 15:12:02]

On 2014/10/17 15:08:25, sgurun wrote:
> mailto:sgurun@chromium.org changed reviewers:
> + mailto:sky@chromium.org

PTAL, thanks!

[sky, 2014-10-20 15:51:56]

LGTM

[sgurun-gerrit only, 2014-10-20 16:12:05]

The CQ bit was checked by sgurun@chromium.org

[commit-bot: I haz the power, 2014-10-20 16:13:22]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/659153003/20001

[commit-bot: I haz the power, 2014-10-20 16:59:30]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-10-20 17:00:13]

Patchset 2 (id:??) landed as
https://crrev.com/d8e1571cb9fc788aedca3358e8370616fe5991ca
Cr-Commit-Position: refs/heads/master@{#300281}