Rename buildflag_headers for consistency

This updates mojo, net and pdf.

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: I279223aa2bdfc375288eee485a77bfad9b6db3d4
Reviewed-on: https://chromium-review.googlesource.com/978372
Commit-Queue: Scott Violet <[email protected]>
Reviewed-by: Daniel Cheng <[email protected]>
Cr-Commit-Position: refs/heads/master@{#545650}
diff --git a/net/BUILD.gn b/net/BUILD.gn
index 6135148..695c1343 100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -47,8 +47,8 @@
 # Python works only on Linux, MacOS and Windows.
 enable_python_utils = !is_android && !is_fuchsia && !is_ios
 
-buildflag_header("features") {
-  header = "net_features.h"
+buildflag_header("buildflags") {
+  header = "net_buildflags.h"
   flags = [
     "POSIX_AVOID_MMAP=$posix_avoid_mmap",
     "DISABLE_FILE_SUPPORT=$disable_file_support",
@@ -2069,7 +2069,7 @@
   configs += net_configs
 
   public_deps += [
-    ":features",
+    ":buildflags",
     "//url",
   ]