Handle storyboards in GN.

build/config/mac/base_rules.gni

Index: build/config/mac/base_rules.gni
diff --git a/build/config/mac/base_rules.gni b/build/config/mac/base_rules.gni
index 92e73a862f66a6b67320a739ae22dd7088e3da46..e75239744f536bd235c00da7a25fcdcadd4d3d74 100644
--- a/build/config/mac/base_rules.gni
+++ b/build/config/mac/base_rules.gni
@@ -202,7 +202,7 @@ template("info_plist") {
   }
 }
 
-# Template to combile .xib or .storyboard files.
+# Template to compile .xib files.
 #
 # Arguments
 #
@@ -226,7 +226,7 @@ template("compile_xibs") {
       ibtool_flags = invoker.ibtool_flags
     }
 
-    script = "//build/config/mac/compile_xib.py"
+    script = "//build/config/mac/compile_ib_files.py"
     sources = invoker.sources
     outputs = [
       "$target_gen_dir/$target_name/{{source_name_part}}.nib",
@@ -246,3 +246,49 @@ template("compile_xibs") {
     args += ibtool_flags
   }
 }
+
+# Template to compile .storyboard files.
+#
+# Arguments
+#
+#     sources:
+#         list of string, sources to compile
+#
+#     ibtool_flags:
+#         (optional) list of string, additional flags to pass to the ibtool
+template("compile_storyboards") {
+  action_foreach(target_name) {
+    forward_variables_from(invoker,
+                           [
+                             "testonly",
+                             "visibility",
+                           ])
+    assert(defined(invoker.sources),
+           "Sources must be specified for $target_name")
+
+    ibtool_flags = []
+    if (defined(invoker.ibtool_flags)) {
+      ibtool_flags = invoker.ibtool_flags
+    }
+
+    script = "//build/config/mac/compile_ib_files.py"
+    sources = invoker.sources
+    outputs = [
+      "$target_gen_dir/$target_name/{{source_name_part}}.storyboardc",
+    ]
+    args = [
+      "--input",
+      "{{source}}",
+      "--output",
+      rebase_path(
+          "$target_gen_dir/$target_name/{{source_name_part}}.storyboardc"),
+    ]
+    if (!use_system_xcode) {
+      args += [
+        "--developer_dir",
+        hermetic_xcode_path,
+      ]
+    }
+    args += ibtool_flags
+  }
+}