Remove RequestTrackerImpl class as unused.

RequestTrackerImpl was needed when Chrome used UIWebView.

Bug: 585700
Change-Id: I755e6377bc05c4f7018cad2fe6ff2c79e6b5d8c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1601665
Auto-Submit: Eugene But <eugenebut@chromium.org>
Reviewed-by: Mike Dougherty <michaeldo@chromium.org>
Commit-Queue: Eugene But <eugenebut@chromium.org>
Cr-Commit-Position: refs/heads/master@{#660070}

ios/web/BUILD.gn

@@ -343,7 +343,6 @@ source_set("ios_web_net_unittests") {
     "net/cookies/wk_http_system_cookie_store_unittest.mm",
     "net/crw_cert_verification_controller_unittest.mm",
     "net/crw_ssl_status_updater_unittest.mm",
-    "net/request_tracker_impl_unittest.mm",
   ]
 }
 

ios/web/net/BUILD.gn

@@ -29,8 +29,6 @@ source_set("net") {
     "crw_cert_verification_controller.mm",
     "crw_ssl_status_updater.h",
     "crw_ssl_status_updater.mm",
-    "request_tracker_impl.h",
-    "request_tracker_impl.mm",
   ]
 
   configs += [ "//build/config/compiler:enable_arc" ]