Fix //content/test:test_support under component builds.

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_handler",
   ]
 }
 
 # In GYP: devtools_resources action in the devtools_resources target.
 grit("devtools_resources") {
   source = "$root_gen_dir/devtools/devtools_resources.grd"
 
   # TOOD(brettw) remove this so the output file goes into the target_gen_dir,
   # but keep this for not for GYP compat.
   output_dir = "$root_gen_dir/blink"
   outputs = [
     "grit/devtools_resources.h",
     "devtools_resources.pak",
     "grit/devtools_resources_map.cc",
     "grit/devtools_resources_map.h",
   ]
 
   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("gen_devtools_protocol_handler") {
-  visibility = [ ":devtools_protocol_handler" ]
+  visibility = [ "//content/browser" ]
 
   script = "//content/browser/devtools/protocol/" +
            "devtools_protocol_handler_generator.py"
 
   blink_protocol = "//third_party/WebKit/Source/devtools/protocol.json"
   browser_protocol = "browser_protocol.json"
   inputs = [
     blink_protocol,
     browser_protocol,
   ]
 
   outputs = [
     "$target_gen_dir/protocol/devtools_protocol_dispatcher.cc",
     "$target_gen_dir/protocol/devtools_protocol_dispatcher.h",
   ]
 
   args =
       rebase_path(inputs, root_build_dir) + rebase_path(outputs, root_build_dir)
 }
-
-source_set("devtools_protocol_handler") {
-  visibility = [ ":resources" ]
-  sources = get_target_outputs(":gen_devtools_protocol_handler")
-}