Update some host_resolver()->AddRules in chrome/browser.

chrome/browser/chromeos/extensions/wallpaper_apitest.cc

Index: chrome/browser/chromeos/extensions/wallpaper_apitest.cc
diff --git a/chrome/browser/chromeos/extensions/wallpaper_apitest.cc b/chrome/browser/chromeos/extensions/wallpaper_apitest.cc
index 10a6f33938f3fa6f54b96db7c6292b77e7d61248..3f0b0cd9949adb1192274130f437d49642559ec6 100644
--- a/chrome/browser/chromeos/extensions/wallpaper_apitest.cc
+++ b/chrome/browser/chromeos/extensions/wallpaper_apitest.cc
@@ -6,10 +6,19 @@
 #include "chromeos/cryptohome/system_salt_getter.h"
 #include "net/dns/mock_host_resolver.h"
 
-IN_PROC_BROWSER_TEST_F(ExtensionApiTest, Wallpaper) {
+class WallPaperApiTest : public ExtensionApiTest {
+ public:
+  ~WallPaperApiTest() override = default;
+
+  void SetUpOnMainThread() override {
+    ExtensionApiTest::SetUpOnMainThread();
+    host_resolver()->AddRule("a.com", "127.0.0.1");
+  }
+};
+
+IN_PROC_BROWSER_TEST_F(WallPaperApiTest, Wallpaper) {
   chromeos::SystemSaltGetter::Get()->SetRawSaltForTesting(
       chromeos::SystemSaltGetter::RawSalt({1, 2, 3, 4, 5, 6, 7, 8}));
-  host_resolver()->AddRule("a.com", "127.0.0.1");
   ASSERT_TRUE(StartEmbeddedTestServer());
   ASSERT_TRUE(RunExtensionTest("wallpaper")) << message_;
 }