chrome: 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
AX-Relnotes: n/a.
Change-Id: If011b89bfb5f3561e152aeee242b0b2fe1ab4587
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2897520
Auto-Submit: Anton Bikineev <[email protected]>
Commit-Queue: Peter Kasting <[email protected]>
Reviewed-by: Peter Kasting <[email protected]>
Owners-Override: Peter Kasting <[email protected]>
Cr-Commit-Position: refs/heads/master@{#883266}
diff --git a/chrome/browser/sharing/sharing_message_sender.h b/chrome/browser/sharing/sharing_message_sender.h
index 8e5ddf3..6878c57 100644
--- a/chrome/browser/sharing/sharing_message_sender.h
+++ b/chrome/browser/sharing/sharing_message_sender.h
@@ -11,8 +11,8 @@
 
 #include "base/callback.h"
 #include "base/memory/weak_ptr.h"
-#include "base/optional.h"
 #include "base/time/time.h"
+#include "third_party/abseil-cpp/absl/types/optional.h"
 
 namespace chrome_browser_sharing {
 enum MessageType : int;
@@ -41,7 +41,7 @@
    public:
     using SendMessageCallback =
         base::OnceCallback<void(SharingSendMessageResult result,
-                                base::Optional<std::string> message_id,
+                                absl::optional<std::string> message_id,
                                 SharingChannelType channel_type)>;
     virtual ~SendMessageDelegate() = default;
 
@@ -107,7 +107,7 @@
 
   void OnMessageSent(const std::string& message_guid,
                      SharingSendMessageResult result,
-                     base::Optional<std::string> message_id,
+                     absl::optional<std::string> message_id,
                      SharingChannelType channel_type);
 
   void InvokeSendMessageCallback(