[Cronet] Use gn desc deps to find third_party licenses.

components/cronet/ios/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.
+
+import("//build/buildflag_header.gni")
+import("//build/util/version.gni")
+import("//chrome/version.gni")
+import("//testing/test.gni")
+import("//url/features.gni")
+
+assert(!is_component_build, "Cronet requires static library build.")
+
+declare_args() {
+  cronet_enable_data_reduction_proxy_support = false
+}
+
+process_version("cronet_version_header") {
+  template_file = "//components/cronet/version.h.in"
+  output = "$target_gen_dir/version.h"
+  extra_args = [
+    "-e",
+    "VERSION_FULL=\"%s.%s.%s.%s\" % (MAJOR,MINOR,BUILD,PATCH)",
+  ]
+}
+
+source_set("cronet_static") {
+  deps = [
+    ":cronet_version_header",
+    "//components/metrics:metrics",
+    "//components/metrics/proto:proto",
+    "//net",
+    "//url",
+  ]
+
+  sources = [
+    "../histogram_manager.cc",
+    "../histogram_manager.h",
+    "../url_request_context_config.cc",
+    "../url_request_context_config.h",
+    "Cronet.h",
+    "Cronet.mm",
+    "cronet_bidirectional_stream.cc",
+    "cronet_bidirectional_stream.h",
+    "cronet_c_for_grpc.cc",
+    "cronet_c_for_grpc.h",
+    "cronet_environment.cc",
+    "cronet_environment.h",
+  ]
+
+  if (!use_platform_icu_alternatives) {
+    deps += [ "//base:i18n" ]
+  }
+}

[kapishnikov, 2016/05/17 22:03:28]

Should we add '-fvisibility=hidden' and '-fvisibility-inlines-hidden' C flags
here or in the 'shared_library' target?

[mef, 2016/05/18 16:46:18]

Symbol visibility=hidden seems to be
default:https://code.google.com/p/chromium/codesearch#chromium/src/build/config/gcc/BUILD.gn&l=18

+
+shared_library("libcronet") {

[kapishnikov, 2016/05/17 22:03:28]

I have renamed the target to 'libcronet_shered' in GYP in order to avoid name
conflicts with Cronet framework: see https://codereview.chromium.org/1985893002/

[mef, 2016/05/18 16:46:18]

Done.

+  sources = [

[kapishnikov, 2016/05/17 22:03:28]

"cronet_static" already lists these sources. Do we need them here?

[mef, 2016/05/18 16:46:19]

Done.

+    "Cronet.h",
+    "Cronet.mm",
+    "cronet_c_for_grpc.cc",
+    "cronet_c_for_grpc.h",
+  ]
+  deps = [
+    ":cronet_static",
+    "//base",
+    "//net:net",
+  ]
+  libs = [ "UIKit.Framework" ]

[kapishnikov, 2016/05/17 22:03:28]

I wonder why we need UIKit.Framework? Will Foundation.framework be enough?

[mef, 2016/05/18 16:46:19]

I'm getting these errors without UIKit:

Undefined symbols for architecture x86_64:
  "_OBJC_CLASS_$_UIApplication", referenced from:
      objc-class-ref in libbase.a(scoped_critical_action.o)
  "_OBJC_CLASS_$_UIDevice", referenced from:
      objc-class-ref in libbase.a(sys_info_ios.o)
      objc-class-ref in libbase.a(critical_closure_internal_ios.o)
  "_UIBackgroundTaskInvalid", referenced from:
      base::ios::ScopedCriticalAction::Core::EndBackgroundTask() in
libbase.a(scoped_critical_action.o)
      base::ios::ScopedCriticalAction::Core::Core() in
libbase.a(scoped_critical_action.o)
      base::ios::ScopedCriticalAction::Core::~Core() in
libbase.a(scoped_critical_action.o)

[kapishnikov, 2016/05/18 17:23:01]

I see. It is used in
https://code.google.com/p/chromium/codesearch#chromium/src/components/history...
to extend CPU allocation when application goes into the background. Not sure if
we need this class in Cronet.

+}
+
+bundle_data("cronet_test_bundle_data") {
+  testonly = true
+  sources = [
+    "//net/data/ssl/certificates/quic_test.example.com.crt",
+    "//net/data/ssl/certificates/quic_test.example.com.key",
+    "//net/data/ssl/certificates/quic_test.example.com.key.pkcs8",
+    "//net/data/ssl/certificates/quic_test.example.com.key.sct",
+  ]
+  outputs = [
+    "{{bundle_resources_dir}}/{{source_file_part}}",
+  ]
+}
+
+test("cronet_test") {
+  testonly = true
+  sources = [
+    "test/cronet_bidirectional_stream_test.mm",
+    "test/cronet_test_runner.mm",
+    "test/quic_test_server.cc",
+    "test/quic_test_server.h",
+  ]
+
+  deps = [
+    ":cronet_static",
+    ":cronet_test_bundle_data",
+    ":cronet_version_header",
+    "//base",
+    "//base:i18n",
+    "//net",
+    "//net:simple_quic_tools",
+    "//net:test_support",
+    "//third_party/icu",
+  ]
+}
+
+test("cronet_unittests") {
+  sources = [
+    "//components/cronet/histogram_manager_unittest.cc",
+    "//components/cronet/run_all_unittests.cc",
+    "//components/cronet/url_request_context_config_unittest.cc",
+  ]
+
+  deps = [
+    ":cronet_static",
+    "//base",
+    "//base/test:test_support",
+    "//components/metrics",
+    "//net",
+    "//testing/gtest",
+  ]
+}
+
+_package_dir = "$root_out_dir/cronet"
+
+action("generate_license") {
+  _license_path = "$_package_dir/LICENSE"
+
+  script = "//components/cronet/tools/cronet_licenses.py"
+  outputs = [
+    _license_path,
+  ]
+  args = [
+    "license",
+    rebase_path(_license_path, root_build_dir),
+    "--gn",
+  ]
+}
+
+copy("cronet_package_copy") {
+  sources = [
+    "//AUTHORS",
+    "//chrome/VERSION",
+    "//components/cronet/ios/Cronet.h",
+    "//components/cronet/ios/cronet_c_for_grpc.h",
+  ]
+  outputs = [
+    "$_package_dir/{{source_file_part}}",
+  ]
+
+  deps = []
+}
+
+group("cronet_package") {
+  deps = [
+    ":cronet_package_copy",
+    ":cronet_static",
+    ":generate_license",
+  ]
+}