net: Replace base::Optional and friends with absl counterparts

This replaces:
- base::Optional -> absl::optional
- include "base/optional.h"
  ->
  include "third_party/abseil-cpp/absl/types/optional.h"
- base::nullopt -> absl::nullopt
- base::make_optional -> absl::make_optional

Bug: 1202909
Change-Id: I27d6f81f415e213c1a4997a55c35935a57ba88a4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2896994
Auto-Submit: Anton Bikineev <[email protected]>
Commit-Queue: Anton Bikineev <[email protected]>
Reviewed-by: Peter Kasting <[email protected]>
Owners-Override: Peter Kasting <[email protected]>
Cr-Commit-Position: refs/heads/master@{#883294}
diff --git a/net/socket/connect_job_unittest.cc b/net/socket/connect_job_unittest.cc
index 5ec9c06..230396e6 100644
--- a/net/socket/connect_job_unittest.cc
+++ b/net/socket/connect_job_unittest.cc
@@ -69,7 +69,7 @@
   int ConnectInternal() override {
     SetSocket(std::unique_ptr<StreamSocket>(new MockTCPClientSocket(
                   AddressList(), net_log().net_log(), &socket_data_provider_)),
-              base::nullopt /* dns_aliases */);
+              absl::nullopt /* dns_aliases */);
     return socket()->Connect(base::BindOnce(
         &TestConnectJob::NotifyDelegateOfCompletion, base::Unretained(this)));
   }