ui: Cleanup class/struct forward declarations

ios/chrome/browser/BUILD.gn

Index: ios/chrome/browser/BUILD.gn
diff --git a/ios/chrome/browser/BUILD.gn b/ios/chrome/browser/BUILD.gn
index be01df0700109c09593eb5802505018b83554121..3af212a9ce95a19c6fadf8148feba4c98374113e 100644
--- a/ios/chrome/browser/BUILD.gn
+++ b/ios/chrome/browser/BUILD.gn
@@ -112,14 +112,6 @@ source_set("browser") {
   libs = [ "UIKit.framework" ]
 }
 
-# TODO(crbug.com/658242): this target is there to avoid breaking downstream
-# when this CL rolls. It should be removed in favor of browser.
-group("browser_no_public_deps") {
-  public_deps = [
-    ":browser",
-  ]
-}
-
 source_set("browser_impl") {
   sources = [
     "application_context_impl.cc",
@@ -150,6 +142,7 @@ source_set("browser_impl") {
     "//components/translate/core/browser",
     "//components/update_client",
     "//components/variations",
+    "//components/variations/field_trial_config",
     "//components/variations/service",
     "//ios/chrome/browser/browser_state",
     "//ios/chrome/browser/browser_state:browser_state_impl",