Do not export sourcemaps to HAR.
Do not export sourcemaps to HAR.

BUG=339810

Review URL: https://codereview.chromium.org/151803003

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@166513 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