Extend LargeIconService to fetch missing favicons from a Google server

ios/chrome/browser/favicon/BUILD.gn

 # Copyright 2016 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.
 
 source_set("favicon") {
   configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "favicon_attributes.h",
     "favicon_attributes.mm",
     "favicon_attributes_provider.h",
@@ skipping 10 matching lines @@
     "ios_chrome_large_icon_cache_factory.h",
     "ios_chrome_large_icon_service_factory.cc",
     "ios_chrome_large_icon_service_factory.h",
     "large_icon_cache.cc",
     "large_icon_cache.h",
   ]
   deps = [
     "//base",
     "//components/favicon/core",
     "//components/favicon_base",
+    "//components/image_fetcher/core",
+    "//components/image_fetcher/ios",
     "//components/keyed_service/core",
     "//components/keyed_service/ios",
     "//components/resources",
     "//ios/chrome/browser",
     "//ios/chrome/browser/browser_state",
     "//ios/chrome/browser/history",
     "//ios/web",
     "//skia",
     "//ui/base",
     "//ui/gfx",
     "//url",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "large_icon_cache_unittest.cc",
   ]
   deps = [
     ":favicon",
     "//base",
     "//components/favicon_base",
     "//skia",
     "//testing/gtest",
     "//ui/gfx",
     "//ui/gfx:test_support",
   ]
 }