Stop linking a static_initializer into the Mac chromium build. The :angle-image_util target was a source_set rather than a static_library(), causing us to link in loadimage.cpp, which pulled in mathutils.cpp, which contains a static initializer. Switching :angle_image_util to a static library (which is what GYP does) solved the problem. R=rsesek@chromium.org, cwallez@chromium.org BUG=628052 Change-Id: I63387b3fc9d799c92f7c1b49a1c7c7435e70a951 Reviewed-on: https://chromium-review.googlesource.com/360228 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Robert Sesek <rsesek@chromium.org> Reviewed-by: Dirk Pranke <dpranke@chromium.org>