third_party-icu-use-system-icu.diff

diff --git a/BUILD.gn b/BUILD.gn
index 1dd7c61..84d265f 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -42,10 +42,19 @@ config("icu_config") {
     defines += [ "U_STATIC_IMPLEMENTATION" ]
   }
 
-  include_dirs = [
-    "source/common",
-    "source/i18n",
-  ]
+  print(current_cpu, target_cpu)
+
+  if (!icu_use_system || current_cpu != target_cpu) {
+     include_dirs = [
+       "source/common",
+       "source/i18n",
+     ]
+  }
+  else {
+     include_dirs = [ "$target_gen_dir/../../unicode" ]
+     lib_dirs = [ icu_lib_dir ]
+     libs = [ "icui18n", "icuuc", "icudata", "c" ]
+  }
 
   if (icu_use_data_file) {
     defines += [ "ICU_UTIL_DATA_IMPL=ICU_UTIL_DATA_FILE" ]
@@ -58,6 +67,18 @@ config("icu_config") {
   }
 }
 
+if (icu_use_system && current_cpu == target_cpu) {
+  copy("icui18n") {
+      sources = [ icu_include_dir ]
+      outputs = [ "$target_gen_dir/../../unicode" ]
+
+      public_configs = [ ":icu_config" ]
+  }
+  group("icuuc") {
+      public_deps = [ ":icui18n" ]
+  }
+}
+else {
 # Config used only by ICU code.
 config("icu_code") {
   cflags = []
@@ -1054,3 +1075,4 @@ if (icu_use_data_file) {
     }
   }
 }
+}
diff --git a/config.gni b/config.gni
index 9c389de..fa54355 100644
--- a/config.gni
+++ b/config.gni
@@ -13,4 +13,14 @@ declare_args() {
   # TODO(GYP) We'll probably need to enhance this logic to set the value to
   # true or false in similar circumstances.
   icu_use_data_file = true
+
+  # Tells that the system version of ICU should be used
+  icu_use_system = false
+
+  # Include directory for system ICU
+  icu_include_dir = "/usr/include/"
+
+  # System library directory for system ICU
+  icu_lib_dir = "/usr/lib"
 }
+