Sync the browser test host resolver with the network process before a test runs.

content/test/BUILD.gn

Index: content/test/BUILD.gn
diff --git a/content/test/BUILD.gn b/content/test/BUILD.gn
index fe8a813f9b87a048a1641c2db1a97ab8a6154788..eea3d4e4201383603d63f7013c10628a480c1076 100644
--- a/content/test/BUILD.gn
+++ b/content/test/BUILD.gn
@@ -106,6 +106,8 @@ static_library("test_support") {
     "../public/test/test_fileapi_operation_waiter.h",
     "../public/test/test_frame_navigation_observer.cc",
     "../public/test/test_frame_navigation_observer.h",
+    "../public/test/test_host_resolver.cc",
+    "../public/test/test_host_resolver.h",
     "../public/test/test_launcher.cc",
     "../public/test/test_launcher.h",
     "../public/test/test_navigation_observer.cc",
@@ -243,6 +245,8 @@ static_library("test_support") {
     "//content/gpu",
     "//content/public/browser",
     "//content/public/child",
+    "//content/public/common:interfaces",
+    "//content/public/common:service_names",
     "//content/public/renderer",
     "//content/public/utility",
     "//content/renderer:for_content_tests",