Add a URLLoaderFactory implementation in src/ios for use by components.

This is backed by services/network/url_loader implementation. This allows components that are
shared with src/chrome to use URLLoader instead of URLFetcher.

Old:
Layered components take BrowserState::GetRequestContext() and pass it to to net::URLFetcher.

New:
Layered components take BrowserState::GetURLLoaderFactory() and pass it to network::SimpleURLLoader.

Bug: 803149
Cq-Include-Trybots: master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs
Change-Id: Ie4723ca17467f0372eed4d999544351152702e3e
Reviewed-on: https://chromium-review.googlesource.com/907543
Commit-Queue: John Abd-El-Malek <[email protected]>
Reviewed-by: Eugene But <[email protected]>
Cr-Commit-Position: refs/heads/master@{#535472}
diff --git a/ios/DEPS b/ios/DEPS
index 0644d46..0c9ccaf 100644
--- a/ios/DEPS
+++ b/ios/DEPS
@@ -17,3 +17,9 @@
   # to crbug.com/708307.
   "-ios/web/public/test/http_server/http_server.h",
 ]
+
+specific_include_rules = {
+  ".*test\.mm": [
+    "+services/network/public/cpp",
+  ],
+}