fiddle: Set HTTP caching headers.
fiddle: Set HTTP caching headers.

BUG=skia:

Review-Url: https://codereview.chromium.org/1927593002

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot