[iOS] Clean deps and public_deps.

ios/public/provider/chrome/browser/BUILD.gn

 # Copyright 2015 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/buildflag_header.gni")
 import("//ios/public/provider/chrome/browser/build_config.gni")
 
 source_set("browser") {
   sources = [
     "chrome_browser_provider.h",
     "chrome_browser_provider.mm",
     "geolocation_updater_provider.h",
     "geolocation_updater_provider.mm",
   ]
   deps = [
     "//base",
     "//components/favicon_base",
     "//components/metrics",
     "//components/sync_sessions",
   ]
   libs = [ "CoreLocation.framework" ]
-
-  # TODO(sdefresne): remove once downstream has been converted to depends
-  # directly on the sub-targets.
-  public_deps = [
-    "//ios/public/provider/chrome/browser/distribution",
-    "//ios/public/provider/chrome/browser/images",
-    "//ios/public/provider/chrome/browser/native_app_launcher",
-    "//ios/public/provider/chrome/browser/omaha",
-    "//ios/public/provider/chrome/browser/sessions",
-    "//ios/public/provider/chrome/browser/signin",
-    "//ios/public/provider/chrome/browser/ui",
-    "//ios/public/provider/chrome/browser/user_feedback",
-    "//ios/public/provider/chrome/browser/voice",
-  ]
-}
-
-buildflag_header("provider_flags") {
-  header = "provider_flags.h"
-  flags = [ "USE_DEFAULT_IOS_PROVIDER=$use_default_ios_provider" ]
 }
 
 source_set("test_support") {
   testonly = true
   sources = [
     "test_chrome_browser_provider.h",
     "test_chrome_browser_provider.mm",
     "test_chrome_provider_initializer.h",
     "test_chrome_provider_initializer.mm",
   ]
@@ skipping 21 matching lines @@
     "//ios/public/provider/chrome/browser/images:test_support",
     "//ios/public/provider/chrome/browser/native_app_launcher:test_support",
     "//ios/public/provider/chrome/browser/omaha:test_support",
     "//ios/public/provider/chrome/browser/sessions:test_support",
     "//ios/public/provider/chrome/browser/signin:test_support",
     "//ios/public/provider/chrome/browser/ui:test_support",
     "//ios/public/provider/chrome/browser/user_feedback:test_support",
     "//ios/public/provider/chrome/browser/voice:test_support",
   ]
 }