Add chrome/browser/extensions to "GN check"

components/data_reduction_proxy/core/browser/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 browser_sources = [
   "data_reduction_proxy_bypass_protocol.cc",
   "data_reduction_proxy_bypass_protocol.h",
   "data_reduction_proxy_bypass_stats.cc",
   "data_reduction_proxy_bypass_stats.h",
   "data_reduction_proxy_compression_stats.cc",
@@ skipping 58 matching lines @@
   }
 }
 
 static_library("browser") {
   sources = browser_sources
   sources += [
     "data_store_impl.cc",
     "data_store_impl.h",
   ]
 
+  public_deps = [
+    "//components/data_reduction_proxy/core/common",
+    "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
+  ]
   deps = [
     "//base",
-    "//components/data_reduction_proxy/core/common",
-    "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
     "//components/pref_registry",
     "//components/prefs",
     "//components/variations",
     "//crypto",
     "//google_apis",
     "//net",
     "//third_party/leveldatabase",
     "//url",
   ]
 
@@ skipping 84 matching lines @@
     "//base/test:test_support",
     "//components/data_reduction_proxy/core/common:test_support",
     "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
     "//components/prefs:test_support",
     "//components/variations",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }