Rename buildflag_header targets in base for consistency

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: Ib936c2840991902fa33c040b381b8ffc98a3c532
Reviewed-on: https://chromium-review.googlesource.com/930033
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Scott Violet <sky@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#538310}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 4416579b311cc64b476335b5d46ddbfa6131ed0e
diff --git a/tools/gn/bootstrap/bootstrap.py b/tools/gn/bootstrap/bootstrap.py
index 35c0945..c013f7d 100755
--- a/tools/gn/bootstrap/bootstrap.py
+++ b/tools/gn/bootstrap/bootstrap.py
@@ -180,13 +180,14 @@
 
   write_buildflag_header_manually(
       root_gen_dir,
-      'base/synchronization/synchronization_flags.h',
+      'base/synchronization/synchronization_buildflags.h',
       {'ENABLE_MUTEX_PRIORITY_INHERITANCE': 'false'})
 
-  write_buildflag_header_manually(root_gen_dir, 'base/allocator/features.h',
+  write_buildflag_header_manually(root_gen_dir, 'base/allocator/buildflags.h',
       {'USE_ALLOCATOR_SHIM': 'true' if is_linux else 'false'})
 
-  write_buildflag_header_manually(root_gen_dir, 'base/debug/debugging_flags.h',
+  write_buildflag_header_manually(root_gen_dir,
+                                  'base/debug/debugging_buildflags.h',
       {
           'ENABLE_LOCATION_SOURCE': 'false',
           'ENABLE_PROFILING': 'false',
@@ -195,10 +196,10 @@
       })
 
   write_buildflag_header_manually(root_gen_dir,
-                                  'base/memory/protected_memory_flags.h',
+                                  'base/memory/protected_memory_buildflags.h',
                                   { 'USE_LLD': 'false' })
 
-  write_buildflag_header_manually(root_gen_dir, 'base/cfi_flags.h',
+  write_buildflag_header_manually(root_gen_dir, 'base/cfi_buildflags.h',
       {
           'CFI_CAST_CHECK': 'false',
           'CFI_ICALL_CHECK': 'false',
@@ -219,7 +220,8 @@
     ])
 
   if is_win:
-    write_buildflag_header_manually(root_gen_dir, 'base/win/base_features.h',
+    write_buildflag_header_manually(root_gen_dir,
+                                    'base/win/base_win_buildflags.h',
         {'SINGLE_MODULE_MODE_HANDLE_VERIFIER': 'true'})
 
     write_compiled_message(root_gen_dir,