Work on Windows GN component build.

ppapi/proxy/BUILD.gn

 # Copyright 2015 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.
 
 config("proxy_implementation") {
   defines = [ "PPAPI_PROXY_IMPLEMENTATION" ]
 }
 
 component("proxy") {
   output_name = "ppapi_proxy"
@@ skipping 254 matching lines @@
 
   configs += [ ":proxy_implementation" ]
 
   deps = [
     "//base",
     "//gpu/command_buffer/client:gles2_implementation",
     "//gpu/ipc",
     "//ipc",
     "//media:shared_memory_support",
     "//ppapi/c",
-    "//ppapi/proxy:ipc",
+    "//ppapi/proxy:ipc_sources",
     "//ppapi/shared_impl",
     "//third_party/icu",
   ]
 
   if (is_nacl) {
     deps += [
       "//ui/events:latency_info",
       "//mojo/nacl:mojo",
     ]
   } else {
     deps += [
       "//base/third_party/dynamic_annotations",
       "//gin",
       "//skia",
       "//ui/events:events_base",
       "//ui/surface",
     ]
   }
 }
 
-source_set("ipc") {
+group("ipc") {
+  if (is_component_build) {
+    public_deps = [
+      "//ppapi/proxy",
+    ]
+  } else {
+    public_deps = [
+      ":ipc_sources",
+    ]
+  }
+}
+
+source_set("ipc_sources") {
   sources = [
     "nacl_message_scanner.cc",
     "nacl_message_scanner.h",
     "ppapi_messages.cc",
     "ppapi_messages.h",
     "ppapi_param_traits.cc",
     "ppapi_param_traits.h",
     "raw_var_data.cc",
     "raw_var_data.h",
     "resource_message_params.cc",
@@ skipping 42 matching lines @@
   deps = [
     "//base/test:test_support",
     "//ipc",
     "//ipc:test_support",
     "//ppapi/proxy",
     "//ppapi/shared_impl",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }