Fix warning in Clang 4.0 Mac build.

    ../src/views/mac/SkNSView.mm:18:31: note: expanded from macro 'RETINA_API_AVAILABLE'
    #define RETINA_API_AVAILABLE (defined(MAC_OS_X_VERSION_10_7) && \
                                  ^
    ../src/views/mac/SkNSView.mm:404:5: error: macro expansion producing 'defined' has undefined behavior [-Werror,-Wexpansion-to-defined]
    #if RETINA_API_AVAILABLE

After this change, Clang 4.0 builds everything on Mac without warning.

Change-Id: I9c8f63e009eaa69366ba9361a811df46a1204c24
Reviewed-on: https://skia-review.googlesource.com/9741
Reviewed-by: Ben Wagner <bungeman@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
1 file changed