Rename buildflag_headers for consistency

This updates printing.

Targets go from foo_features to foo_buildflags
And similarly the header now has buildflags in the name.

BUG=814485
TEST=covered by build

Change-Id: I455c5638ef9bcd98f669fc7117b4699a34292fd0
Reviewed-on: https://chromium-review.googlesource.com/988132
Reviewed-by: Daniel Cheng <[email protected]>
Commit-Queue: Scott Violet <[email protected]>
Cr-Commit-Position: refs/heads/master@{#547228}
diff --git a/chrome/browser/extensions/BUILD.gn b/chrome/browser/extensions/BUILD.gn
index c04aafb..0d222ef 100644
--- a/chrome/browser/extensions/BUILD.gn
+++ b/chrome/browser/extensions/BUILD.gn
@@ -868,7 +868,7 @@
     "//media:media_buildflags",
     "//net",
     "//ppapi/buildflags",
-    "//printing/features",
+    "//printing/buildflags",
     "//rlz/features",
     "//services/audio/public/cpp",
     "//services/data_decoder/public/cpp",