gcapi_mac: Add gn build file.

chrome/installer/gcapi_mac/BUILD.gn

+# Copyright 2017 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/config/sysroot.gni")
+
+assert(is_mac)
+
+config("gcapi_config") {
+  cflags = [
+    "-isysroot",
+    sysroot,
+    "-mmacosx-version-min=10.5",
+  ]
+  ldflags = [
+    "-isysroot",
+    sysroot,
+    "-mmacosx-version-min=10.5",
+  ]
+}
+
+static_library("gcapi_lib") {
+  complete_static_lib = true
+  sources = [
+    "gcapi.h",
+    "gcapi.mm",
+  ]
+
+  libs = [ "Cocoa.framework" ]
+
+  # Don't use runtime_library, to be able to pick a custom mmacosx-version-min.
+  configs -= [ "//build/config/compiler:runtime_library" ]
+  configs += [ ":gcapi_config" ]
+}
+
+executable("gcapi_example") {
+  sources = [
+    "gcapi_example_client.mm",
+  ]
+
+  deps = [
+    ":gcapi_lib",
+  ]
+
+  # Don't use runtime_library, to be able to pick a custom mmacosx-version-min.
+  configs -= [ "//build/config/compiler:runtime_library" ]
+  configs += [ ":gcapi_config" ]
+}