[iOS] Always generate the final binaries using lipo.

build/toolchain/mac/BUILD.gn

Index: build/toolchain/mac/BUILD.gn
diff --git a/build/toolchain/mac/BUILD.gn b/build/toolchain/mac/BUILD.gn
index d3b0eeba68e0fb9a189aaec3a8e2005096f30b79..348c3b3666dfb7e3d8ebec236786ee12e6a36973 100644
--- a/build/toolchain/mac/BUILD.gn
+++ b/build/toolchain/mac/BUILD.gn
@@ -91,15 +91,15 @@ template("mac_toolchain") {
         "TOOL_VERSION=${tool_versions.linker_driver} " +
         rebase_path("//build/toolchain/mac/linker_driver.py", root_build_dir)
 
-    if (invoker.toolchain_os == "ios" && additional_toolchains != []) {
-      # For a fat build, the generation of dSYM needs to be performed after the
-      # generation of the fat binaries using "lipo". So disable the generation
-      # of the dSYM for intermediate architecture specific binaries.
-      _enable_dsyms = false
-      _save_unstripped_output = false
-    } else {
+    # On iOS, the final applications are assembled using lipo (to support fat
+    # builds). The correct flags are passed to the linker_driver.py script
+    # directly during the lipo call.
+    if (invoker.toolchain_os != "ios") {
       _enable_dsyms = enable_dsyms
       _save_unstripped_output = save_unstripped_output
+    } else {
+      _enable_dsyms = false
+      _save_unstripped_output = false
     }
 
     # Make these apply to all tools below.