[iOS/GN] Fix generation of .dSYM for fat binary builds.

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 72485c050293c84a15d071fe4a330ea62b4a5395..63deb4deaea9edea79c80678d9a94ee7d1c4a9e0 100644
--- a/build/toolchain/mac/BUILD.gn
+++ b/build/toolchain/mac/BUILD.gn
@@ -102,7 +102,7 @@ template("mac_toolchain") {
     object_subdir = "{{target_out_dir}}/{{label_name}}"
 
     # If dSYMs are enabled, this flag will be added to the link tools.
-    if (enable_dsyms) {
+    if (enable_dsyms && (!is_ios || additional_toolchains == [])) {
       dsym_switch = " -Wcrl,dsym," + rebase_path(root_out_dir) + " "
     } else {
       dsym_switch = ""
@@ -231,7 +231,7 @@ template("mac_toolchain") {
       link_output = dylib
       depend_output = tocname
 
-      if (enable_dsyms) {
+      if (enable_dsyms && (!is_ios || additional_toolchains == [])) {
         outputs += [ "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.dSYM/" ]
       }
     }
@@ -262,7 +262,7 @@ template("mac_toolchain") {
         sofile,
       ]
 
-      if (enable_dsyms) {
+      if (enable_dsyms && (!is_ios || additional_toolchains == [])) {
         outputs += [ "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.dSYM/" ]
       }
     }
@@ -286,7 +286,7 @@ template("mac_toolchain") {
         outfile,
       ]
 
-      if (enable_dsyms) {
+      if (enable_dsyms && (!is_ios || additional_toolchains == [])) {
         outputs += [ "{{root_out_dir}}/{{target_output_name}}{{output_extension}}.dSYM/" ]
       }