Add compiling chrome/browser to GN build on Linux.

chrome/browser/sync_file_system/BUILD.gn

Index: chrome/browser/sync_file_system/BUILD.gn
diff --git a/content/browser/service_worker/BUILD.gn b/chrome/browser/sync_file_system/BUILD.gn
similarity index 59%
copy from content/browser/service_worker/BUILD.gn
copy to chrome/browser/sync_file_system/BUILD.gn
index d9f206615fb571677be606d30992a43a6e41f36d..9e07436f3ff9879488a1e6f88043bfb811068057 100644
--- a/content/browser/service_worker/BUILD.gn
+++ b/chrome/browser/sync_file_system/BUILD.gn
@@ -4,9 +4,7 @@
 
 import("//third_party/protobuf/proto_library.gni")
 
-proto_library("database_proto") {
-  sources = [
-    "service_worker_database.proto",
-  ]
+# GYP version: chrome/chrome_browser.gypi:sync_file_system_proto
+proto_library("sync_file_system_proto") {
+  sources = [ "sync_file_system.proto" ]
 }
-