Split up ios/web:test_support.

ios/chrome/browser/test/BUILD.gn

Index: ios/chrome/browser/test/BUILD.gn
diff --git a/ios/chrome/browser/test/BUILD.gn b/ios/chrome/browser/test/BUILD.gn
index 4526196543dcf58a099795a247839b93735cf9c9..1066e4ad3abc0c532bc6ec7ac3e372b8e9c1f267 100644
--- a/ios/chrome/browser/test/BUILD.gn
+++ b/ios/chrome/browser/test/BUILD.gn
@@ -25,7 +25,7 @@ source_set("perf_test_support") {
     "//ios/chrome/test:test_support",
     "//ios/chrome/test/base:perf_test_support",
     "//ios/public/provider/chrome/browser",
-    "//ios/web:test_support",
+    "//ios/web/public/test:test_support",
 
     # Perf tests can run with any provider, but the resulting numbers will only
     # be meaningful if ChromeBrowserProviderImpl is used.