DevTools: Fix broken sourcemap reload after r151612
DevTools: Fix broken sourcemap reload after r151612

R=vsevik@chromium.org, yurys@chromium.org
BUG=none

Review URL: https://codereview.chromium.org/16622004

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@152144 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs