Hook up content/browser compile in GN build.

tools/gn/secondary/tools/grit/grit_rule.gni

Index: tools/gn/secondary/tools/grit/grit_rule.gni
diff --git a/tools/gn/secondary/tools/grit/grit_rule.gni b/tools/gn/secondary/tools/grit/grit_rule.gni
index b75c72ceccdc75f8f0f4a4ccb0e5698afd6a8fdc..f375574f4c3e87bb0bb050c100b33c33acebbbaf 100644
--- a/tools/gn/secondary/tools/grit/grit_rule.gni
+++ b/tools/gn/secondary/tools/grit/grit_rule.gni
@@ -34,6 +34,7 @@ if (is_android) {
   ]
 }
 
+grit_resource_id_file = "//tools/gritsettings/resource_ids"
 grit_info_script = "//tools/grit/grit_info.py"
 
 template("grit") {
@@ -46,7 +47,7 @@ template("grit") {
   # These are all passed as arguments to the script so have to be relative to
   # the build directory.
   resource_ids =
-    rebase_path("//tools/gritsettings/resource_ids", root_build_dir)
+    rebase_path(grit_resource_id_file, root_build_dir)
   output_dir = rebase_path(target_gen_dir, root_build_dir)
   source_path = rebase_path(invoker.source, root_build_dir)
 
@@ -60,7 +61,9 @@ template("grit") {
     [ "--inputs", source_path, "-f", resource_ids] + grit_flags, "list lines")
   # The inputs are relative to the current (build) directory, rebase to
   # the current one.
-  grit_inputs = rebase_path(grit_inputs_build_rel, ".", root_build_dir)
+  grit_inputs = rebase_path(grit_inputs_build_rel, ".", root_build_dir) + [
+    grit_resource_id_file,
+  ]
 
   grit_outputs_build_rel = exec_script(grit_info_script,
     [ "--outputs", "$output_dir", source_path, "-f", resource_ids ] +