Rename USE_NSS to USE_NSS_CERTS.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 5dfddc7d19e4ee0f2cba074a750a137daee203a0..8263e6f17ddef7c5b04271389024730de6cf30e7 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -2998,8 +2998,7 @@
         'defines': ['USE_GLIB=1'],
       }],
       ['<(use_nss_certs)==1 and >(nacl_untrusted_build)==0', {
-        # TODO(davidben): Rename this to USE_NSS_CERTS. https://crbug.com/462040
-        'defines': ['USE_NSS=1'],
+        'defines': ['USE_NSS_CERTS=1'],

[Nico, 2015/04/16 16:33:11]

If you felt cautious, you could define both in this CL and then reland the
removal of the USE_NSS define in a separate CL. If you need to revert, you would
have less churn then.

[davidben, 2015/04/16 18:32:01]

Yeah, that's a good idea. I think even just the rename here will cause a little
bit of churn. There's one place I found where CrOS has to manually set all the
OS_FOO and USE_FOO flags. But I guess they'll notice a build failure and sort it
out.

Revised plan: I'll still send the PSA when this lands so downstreams can rename
as soon as they take this pair of CLs without making automated rolls sad. Then
I'll land the removal of the deprecated ones a day or two later.

       }],
       ['<(chromeos)==1 and >(nacl_untrusted_build)==0', {
         'defines': ['OS_CHROMEOS=1'],