Add missing base files to GN build.

content/browser/devtools/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//tools/grit/grit_rule.gni")
 
 # In GYP: devtools_resources target.
 group("resources") {
   deps = [
     ":devtools_resources",
     ":devtools_protocol_constants",
   ]
 }
 
 # In GYP: devtools_resources action in the devtools_resources target.
-action("devtools_resources") {
-  visibility = ":resources"
+grit("devtools_resources") {
+  source = "$root_gen_dir/devtools/devtools_resources.grd"
 
-  # This can't use grit_rule.gni because the grd file is generated at build
-  # time, so the trick of using grit_info to get the real inputs/outputs at GYP
-  # time isn't possible.
-  script = "//tools/grit/grit.py"
-
-  grdfile = "$root_gen_dir/devtools/devtools_resources.grd"
-
-  inputs = [ grdfile ] +
-    rebase_path(exec_script("//tools/grit/grit_info.py", [ "--inputs" ],
-                            "list lines"),
-                ".", "//")
-
-  out_dir = "$root_gen_dir/webkit"
+  output_dir = "$root_gen_dir/webkit"
   outputs = [
-    "$out_dir/grit/devtools_resources.h",
-    "$out_dir/devtools_resources.pak",
-    "$out_dir/grit/devtools_resources_map.cc",
-    "$out_dir/grit/devtools_resources_map.h",
+    "grit/devtools_resources.h",
+    "devtools_resources.pak",
+    "grit/devtools_resources_map.cc",
+    "grit/devtools_resources_map.h",
   ]
 
-  args = [
-    "-i", rebase_path(grdfile, root_build_dir), "build",
-    "-f", rebase_path("//tools/gritsettings/resource_ids", root_build_dir),
-    "-o", rebase_path(out_dir, root_build_dir),
-    "-D", "SHARED_INTERMEDIATE_DIR=" +
-      rebase_path(root_gen_dir, root_build_dir),
-  ] + grit_defines
+  defines = [
+    "SHARED_INTERMEDIATE_DIR=" + rebase_path(root_gen_dir, root_build_dir),
+  ]
 
   deps = [
     # This is the action that generates out .grd input file.
     "//third_party/WebKit/public:blink_generate_devtools_grd",
   ]
 }
 
 action("devtools_protocol_constants") {
   visibility = ":resources"
 
   script = "//content/public/browser/devtools_protocol_constants_generator.py"
 
   blink_protocol = "//third_party/WebKit/Source/devtools/protocol.json"
   browser_protocol = "browser_protocol.json"
   inputs = [ blink_protocol, browser_protocol ]
 
   outputs = [
     "$target_gen_dir/devtools_protocol_constants.cc",
     "$target_gen_dir/devtools_protocol_constants.h",
   ]
 
   args = [ "content" ] + rebase_path(outputs, root_build_dir) + [
     rebase_path(blink_protocol, root_build_dir),
     rebase_path(browser_protocol, root_build_dir),
   ]
 }