GOOGLE3 -> SK_BUILD_FOR_GOOGLE3

This is more consistent with our other SK_BUILD_FOR_... macros,
and less likely to collide with other preprocessor logic.

(Luckily, this was defined in public.bzl, so we can do this
all in one CL in the Skia repo.)

Change-Id: I5f232888288c9c53fad445545d983d0fb0b4add8
Reviewed-on: https://skia-review.googlesource.com/86940
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Klein <mtklein@chromium.org>
diff --git a/public.bzl b/public.bzl
index c346d74..1e28940 100644
--- a/public.bzl
+++ b/public.bzl
@@ -576,7 +576,7 @@
       # Chrome DEFINES.
       "SK_USE_FREETYPE_EMBOLDEN",
       # Turn on a few Google3-specific build fixes.
-      "GOOGLE3",
+      "SK_BUILD_FOR_GOOGLE3",
       # Required for building dm.
       "GR_TEST_UTILS",
       # Staging flags for API changes