[ios] Mark Chrome target as supporting "catalyst" in Xcode project

Since Chrome can be build for "catalyst" environment, add the key
SUPPORTS_MACCATALYST to the generated Xcode project.

Bug: 1138425
Change-Id: Idb56060a53266f5b9a4ab6a2328970cfa84973de
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2518858Reviewed-by: Olivier Robin <olivierrobin@chromium.org>
Commit-Queue: Sylvain Defresne <sdefresne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824397}

build/config/ios/rules.gni

@@ -681,6 +681,7 @@ template("ios_app_bundle") {
                              "output_name",
                              "product_type",
                              "visibility",
+                             "xcode_extra_attributes",
                            ])
 
     visibility = [ ":$_arch_executable_target" ]
@@ -726,6 +727,7 @@ template("ios_app_bundle") {
                              "product_type",
                              "sources",
                              "visibility",
+                             "xcode_extra_attributes",
                            ])
 
     visibility = [ ":$_lipo_executable_target($_primary_toolchain)" ]
@@ -888,6 +890,7 @@ template("ios_app_bundle") {
                                  "public_deps",
                                  "testonly",
                                  "visibility",
+                                 "xcode_extra_attributes",
                                ])
 
         output_name = _output_name

ios/chrome/app/BUILD.gn

@@ -379,6 +379,10 @@ ios_app_bundle("chrome") {
     variants = ios_chrome_app_variants
   }
 
+  xcode_extra_attributes = {
+    SUPPORTS_MACCATALYST = "YES"
+  }
+
   deps = [
     ":main",
     ":tests_fake_hook",