Allow generation of a chromium outdirs when enable_extensions=false

BUILD.gn

Index: BUILD.gn
diff --git a/BUILD.gn b/BUILD.gn
index ed615866e5b79c0bca197804eb01ae0dd02e14a9..b03008a3011d2607cbfe2a8a28ae3218364ed2fc 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -92,6 +92,13 @@ group("gn_all") {
     ]
   }
 
+  if (enable_extensions) {
+    deps += [
+      "//extensions:extensions_browsertests",
+      "//extensions:extensions_unittests",
+    ]
+  }
+
   if (!is_ios && !is_android && !is_chromecast && !is_fuchsia) {
     deps += [
       "//chrome",
@@ -101,8 +108,6 @@ group("gn_all") {
       "//chrome/test/chromedriver:chromedriver_unittests",
       "//components/sync/tools:sync_client",
       "//components/sync/tools:sync_listen_notifications",
-      "//extensions:extensions_browsertests",
-      "//extensions:extensions_unittests",
       "//gpu/gles2_conform_support:gles2_conform_test",
       "//gpu/khronos_glcts_support:khronos_glcts_test",
       "//jingle:jingle_unittests",