Use bundle_data and create_bundle to add support for iOS app bundle.

base/BUILD.gn

Index: base/BUILD.gn
diff --git a/base/BUILD.gn b/base/BUILD.gn
index 0b41b0e4a8c93c766501839b81c576d5c8d3cdc9..bb9e0723ad3477304d01e206e04ed20eb9af9ce5 100644
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -1606,6 +1606,17 @@ if (is_win) {
   }
 }
 
+if (is_ios) {
+  bundle_data("base_unittests_bundle_data") {
+    sources = [
+      "test/data",
+    ]
+    outputs = [
+      "{{bundle_resources_dir}}/{{source_root_relative_dir}}/{{source_file_part}}",
+    ]
+  }
+}
+
 test("base_unittests") {
   sources = [
     "allocator/tcmalloc_unittest.cc",
@@ -1866,6 +1877,10 @@ test("base_unittests") {
     "//third_party/icu",
   ]
 
+  if (is_ios) {
+    deps += [ ":base_unittests_bundle_data" ]
+  }
+
   # Some unittests depend on the ALLOCATOR_SHIM macro.
   configs += [ "//base/allocator:allocator_shim_define" ]