[BackgroundSync] Initial land of the BackgroundSyncManager

content/browser/background_sync/BUILD.gn

Index: content/browser/background_sync/BUILD.gn
diff --git a/third_party/apple_sample_code/BUILD.gn b/content/browser/background_sync/BUILD.gn
similarity index 60%
copy from third_party/apple_sample_code/BUILD.gn
copy to content/browser/background_sync/BUILD.gn
index 81b7ed013cb3414a9935e25028408110764d31fb..55aeded7a53a4379bfa84619a1796410c1e7a0fa 100644
--- a/third_party/apple_sample_code/BUILD.gn
+++ b/content/browser/background_sync/BUILD.gn
@@ -2,11 +2,10 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("apple_sample_code") {
+import("//third_party/protobuf/proto_library.gni")
+
+proto_library("background_sync_proto") {
   sources = [
-    "ImageAndTextCell.h",
-    "ImageAndTextCell.m",
+    "background_sync.proto",
   ]
-
-  libs = [ "AppKit.framework" ]
 }