remoting: Replace base::MakeUnique with std::make_unique

Should use std::make_unique directly instead of using base::MakeUnique
since August[1]. So, this change removes usages of base::MakeUnique in
//chrome/browser/remoting.

This change removes `#include "base/memory/ptr_util.h"` if it's no more
used in files. (Might not remove if base::WrapUnique is used)

This change also adds `#include <memory>` header except the following
two cases:
  - Not add the header if the file contains the <memory> header
  - Not add the header if the related header contains <memory> header
    (The style guide[2] says that foo.cc can rely on foo.h's includes)

Confirmed no additional lint errors(by `git cl lint`) after this change.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/616016
[2] https://google.github.io/styleguide/cppguide.html#Names_and_Order_of_Includes

Bug: 755727
Change-Id: I78a995a4e57c8c2111c09239cb85225f7f84ee2e
Reviewed-on: https://chromium-review.googlesource.com/874030
Reviewed-by: Gary Kacmarcik <[email protected]>
Commit-Queue: Jinho Bang <[email protected]>
Cr-Commit-Position: refs/heads/master@{#530328}
diff --git a/remoting/host/setup/host_starter.cc b/remoting/host/setup/host_starter.cc
index 7b76356..2b33db7 100644
--- a/remoting/host/setup/host_starter.cc
+++ b/remoting/host/setup/host_starter.cc
@@ -4,6 +4,7 @@
 
 #include "remoting/host/setup/host_starter.h"
 
+#include <memory>
 #include <utility>
 
 #include "base/bind.h"
@@ -43,8 +44,8 @@
     const std::string& chromoting_hosts_url,
     net::URLRequestContextGetter* url_request_context_getter) {
   return base::WrapUnique(new HostStarter(
-      base::MakeUnique<gaia::GaiaOAuthClient>(url_request_context_getter),
-      base::MakeUnique<remoting::ServiceClient>(chromoting_hosts_url,
+      std::make_unique<gaia::GaiaOAuthClient>(url_request_context_getter),
+      std::make_unique<remoting::ServiceClient>(chromoting_hosts_url,
                                                 url_request_context_getter),
       remoting::DaemonController::Create()));
 }