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

content/public/test/browser_test_base.h

Index: content/public/test/browser_test_base.h
diff --git a/content/public/test/browser_test_base.h b/content/public/test/browser_test_base.h
index a404d0f5a1a56d5756e1de610d609b0703cfd3b5..30f7f0a93d5e489a033896652036f4c7f7debd01 100644
--- a/content/public/test/browser_test_base.h
+++ b/content/public/test/browser_test_base.h
@@ -9,6 +9,7 @@
 #include "base/compiler_specific.h"
 #include "base/threading/thread.h"
 #include "build/build_config.h"
+#include "content/public/test/test_host_resolver.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "net/test/spawned_test_server/spawned_test_server.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -18,10 +19,6 @@ class CommandLine;
 class FilePath;
 }
 
-namespace net {
-class RuleBasedHostResolverProc;
-}  // namespace net
-
 namespace content {
 
 class BrowserTestBase : public testing::Test {
@@ -51,7 +48,7 @@ class BrowserTestBase : public testing::Test {
   // Returns the host resolver being used for the tests. Subclasses might want
   // to configure it inside tests.
   net::RuleBasedHostResolverProc* host_resolver() {
-    return rule_based_resolver_.get();
+    return test_host_resolver_->host_resolver();
   }
 
  protected:
@@ -138,6 +135,10 @@ class BrowserTestBase : public testing::Test {
  private:
   void ProxyRunTestOnMainThreadLoop();
 
+  // When using the network process, update the host resolver rules that were
+  // added in SetUpOnMainThread.
+  void InitializeNetworkProcess();
+
   // Testing server, started on demand.
   std::unique_ptr<net::SpawnedTestServer> spawned_test_server_;
 
@@ -145,7 +146,7 @@ class BrowserTestBase : public testing::Test {
   std::unique_ptr<net::EmbeddedTestServer> embedded_test_server_;
 
   // Host resolver used during tests.
-  scoped_refptr<net::RuleBasedHostResolverProc> rule_based_resolver_;
+  std::unique_ptr<TestHostResolver> test_host_resolver_;
 
   // Expected exit code (default is 0).
   int expected_exit_code_;