Enable jumbo/unity build for various //extensions targets

Change-Id: I4685aaade618b0ea68750688eeca2fc0d24364c9
Reviewed-on: https://chromium-review.googlesource.com/922821
Commit-Queue: Jens Widell <[email protected]>
Reviewed-by: Ken Rockot <[email protected]>
Cr-Commit-Position: refs/heads/master@{#537786}
diff --git a/extensions/BUILD.gn b/extensions/BUILD.gn
index 30b71904..40513f36 100644
--- a/extensions/BUILD.gn
+++ b/extensions/BUILD.gn
@@ -1,6 +1,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/jumbo.gni")
 import("//extensions/features/features.gni")
 import("//testing/test.gni")
 import("//tools/grit/grit_rule.gni")
@@ -56,7 +57,7 @@
   ]
 }
 
-static_library("test_support") {
+jumbo_static_library("test_support") {
   testonly = true
   sources = [
     "browser/api/declarative/test_rules_registry.cc",