Exclude reflector_impl_unittest.cc from GN non-Aura, non-Mac builds.
Exclude reflector_impl_unittest.cc from GN non-Aura, non-Mac builds.

This fixes the GN build on Android after https://codereview.chromium.org/846063002.

(The GYP build didn't break because content/browser/compositor/ is completely excluded there; see https://code.google.com/p/chromium/codesearch#chromium/src/content/content_tests.gypi&sq=package:chromium&&type=cs&l=1099)

TBR=bauerb@chromium.org

Review URL: https://codereview.chromium.org/879543002

Cr-Commit-Position: 972c6d2dc6dd5efdad1377c0d224e03eb8f276f7@{#313074}

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