Add support for Mac/iOS application bundles to GN tool.

tools/gn/commands.cc

Index: tools/gn/commands.cc
diff --git a/tools/gn/commands.cc b/tools/gn/commands.cc
index ed7a009d6af2c6f7a866d7d82e753b701d07760e..4806712e21ddaa020134387a7fb464a109d11f23 100644
--- a/tools/gn/commands.cc
+++ b/tools/gn/commands.cc
@@ -206,6 +206,10 @@ bool GetTargetTypeFilter(Target::OutputType* type) {
     *type = Target::COPY_FILES;
     return true;
   }
+  if (value == "copy_bundle_data") {
+    *type = Target::COPY_BUNDLE_DATA;
+    return true;
+  }
   if (value == "action") {
     *type = Target::ACTION;
     return true;