Remove CookieStoreIOS unused constructor

The internal chrome_signin_cookie_manager.mm is converted to the constructor
with NetLog. The constructor with one param is now unused. This CL removes it.

Bug: 801910
Cq-Include-Trybots: luci.chromium.try:ios-simulator-full-configs;master.tryserver.chromium.android:android_cronet_tester;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: Icf1ff6df91a37b6f914e60f29ac6757760cb7a2a
Reviewed-on: https://chromium-review.googlesource.com/1187387Reviewed-by: Rohit Rao <rohitrao@chromium.org>
Commit-Queue: Helen Li <xunjieli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585828}

components/cronet/ios/cronet_environment.mm

@@ -377,9 +377,8 @@ void CronetEnvironment::InitializeOnNetworkThread() {
   // of changing it.
   [[NSHTTPCookieStorage sharedHTTPCookieStorage]
       setCookieAcceptPolicy:NSHTTPCookieAcceptPolicyAlways];
-  std::unique_ptr<net::CookieStore> cookie_store =
-      std::make_unique<net::CookieStoreIOS>(
-          [NSHTTPCookieStorage sharedHTTPCookieStorage]);
+  auto cookie_store = std::make_unique<net::CookieStoreIOS>(
+      [NSHTTPCookieStorage sharedHTTPCookieStorage], nullptr /* net_log */);
   context_builder.SetCookieAndChannelIdStores(std::move(cookie_store), nullptr);
 
   context_builder.set_enable_brotli(brotli_enabled_);

ios/net/cookies/cookie_store_ios.h

@@ -64,10 +64,6 @@ class CookieStoreIOS : public net::CookieStore,
                  NetLog* net_log);
 
   // Used by ChromeSigninCookieManager/Cronet.
-  // TODO(crbug.com/801910): Remove this constructor once the internal
-  // chrome_signin_cookie_manager.mm is converted to using the one with NetLog.
-  explicit CookieStoreIOS(NSHTTPCookieStorage* ns_cookie_store);
-
   // TODO(crbug.com/759226): Remove once the migration to use SystemCookieStore
   // is finished.
   CookieStoreIOS(NSHTTPCookieStorage* ns_cookie_store, NetLog* net_log);

ios/net/cookies/cookie_store_ios.mm

@@ -229,10 +229,6 @@ CookieStoreIOS::CookieStoreIOS(
                      std::move(system_cookie_store),
                      net_log) {}
 
-CookieStoreIOS::CookieStoreIOS(NSHTTPCookieStorage* ns_cookie_store)
-    : CookieStoreIOS(std::make_unique<NSHTTPSystemCookieStore>(ns_cookie_store),
-                     nullptr /* net_log */) {}
-
 CookieStoreIOS::CookieStoreIOS(NSHTTPCookieStorage* ns_cookie_store,
                                NetLog* net_log)
     : CookieStoreIOS(std::make_unique<NSHTTPSystemCookieStore>(ns_cookie_store),