Split up ios/web:test_support.

ios/chrome/browser/metrics/BUILD.gn

Index: ios/chrome/browser/metrics/BUILD.gn
diff --git a/ios/chrome/browser/metrics/BUILD.gn b/ios/chrome/browser/metrics/BUILD.gn
index f9703b044242ede16329ab67b0cc25e30a55b2ba..3ac24ce3a5ea3b13fc09fce6a2ae2053df4c7fa8 100644
--- a/ios/chrome/browser/metrics/BUILD.gn
+++ b/ios/chrome/browser/metrics/BUILD.gn
@@ -78,6 +78,7 @@ source_set("unit_tests") {
     "//components/prefs:test_support",
     "//components/version_info",
     "//ios/chrome/test:test_support",
+    "//ios/web/public/test",
     "//testing/gtest",
   ]
 }
@@ -145,7 +146,7 @@ source_set("unit_tests_internal") {
     "//ios/chrome/browser/ui",
     "//ios/testing:ocmock_support",
     "//ios/web",
-    "//ios/web:test_support",
+    "//ios/web/public/test",
     "//testing/gtest",
     "//third_party/ocmock",
   ]
@@ -171,7 +172,8 @@ source_set("eg_tests") {
     "//ios/chrome/test/earl_grey:test_support",
     "//ios/testing:ios_test_support",
     "//ios/web:earl_grey_test_support",
-    "//ios/web:test_support",
+    "//ios/web/public/test",
+    "//ios/web/public/test/http_server",
     "//ui/base",
     "//url",
   ]
@@ -192,7 +194,7 @@ source_set("external_url_eg_tests") {
     ":test_support",
     "//ios/chrome/test/app:test_support",
     "//ios/chrome/test/earl_grey:test_support",
-    "//ios/web:test_support",
+    "//ios/web/public/test/http_server",
   ]
   libs = [ "XCTest.framework" ]
 }