Use base::ResetAndReturn() in remoting.

base::ResetAndReturn() makes code shorter and simpler. Also in several
places callbacks were Reset() after Run(), which is dangerous for
callback that are allowed to delete the caller. base::ResetAndReturn()
helps to avoid this issue.

Review URL: https://codereview.chromium.org/1064863004

Cr-Commit-Position: refs/heads/master@{#326940}

3 files changed, 15 insertions, 24 deletions

diff --git a/remoting/host/setup/daemon_controller_delegate_mac.mm b/remoting/host/setup/daemon_controller_delegate_mac.mm
index 2fd7daa..9821f86 100644
--- a/remoting/host/setup/daemon_controller_delegate_mac.mm
+++ b/remoting/host/setup/daemon_controller_delegate_mac.mm
@@ -12,6 +12,7 @@
 
 #include "base/basictypes.h"
 #include "base/bind.h"
+#include "base/callback_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
@@ -175,12 +176,10 @@ void DaemonControllerDelegateMac::PreferencePaneCallbackDelegate(
     return;
   }
 
-  DCHECK(!current_callback_.is_null());
-  DaemonController::CompletionCallback done = current_callback_;
-  current_callback_.Reset();
-  done.Run(result);
-
   DeregisterForPreferencePaneNotifications();
+
+  DCHECK(!current_callback_.is_null());
+  base::ResetAndReturn(&current_callback_).Run(result);
 }
 
 // static
diff --git a/remoting/host/setup/host_starter.cc b/remoting/host/setup/host_starter.cc
index 127c4a9..5eda05c 100644
--- a/remoting/host/setup/host_starter.cc
+++ b/remoting/host/setup/host_starter.cc
@@ -5,6 +5,7 @@
 #include "remoting/host/setup/host_starter.h"
 
 #include "base/bind.h"
+#include "base/callback_helpers.h"
 #include "base/guid.h"
 #include "base/location.h"
 #include "base/thread_task_runner_handle.h"
@@ -184,9 +185,7 @@ void HostStarter::OnHostStarted(DaemonController::AsyncResult result) {
     service_client_->UnregisterHost(host_id_, access_token_, this);
     return;
   }
-  CompletionCallback cb = on_done_;
-  on_done_.Reset();
-  cb.Run(START_COMPLETE);
+  base::ResetAndReturn(&on_done_).Run(START_COMPLETE);
 }
 
 void HostStarter::OnOAuthError() {
@@ -195,14 +194,12 @@ void HostStarter::OnOAuthError() {
         &HostStarter::OnOAuthError, weak_ptr_));
     return;
   }
-  CompletionCallback cb = on_done_;
-  on_done_.Reset();
   if (unregistering_host_) {
     LOG(ERROR) << "OAuth error occurred when unregistering host.";
-    cb.Run(START_ERROR);
-  } else {
-    cb.Run(OAUTH_ERROR);
   }
+
+  base::ResetAndReturn(&on_done_)
+      .Run(unregistering_host_ ? START_ERROR : OAUTH_ERROR);
 }
 
 void HostStarter::OnNetworkError(int response_code) {
@@ -211,14 +208,12 @@ void HostStarter::OnNetworkError(int response_code) {
         &HostStarter::OnNetworkError, weak_ptr_, response_code));
     return;
   }
-  CompletionCallback cb = on_done_;
-  on_done_.Reset();
   if (unregistering_host_) {
     LOG(ERROR) << "Network error occurred when unregistering host.";
-    cb.Run(START_ERROR);
-  } else {
-    cb.Run(NETWORK_ERROR);
   }
+
+  base::ResetAndReturn(&on_done_)
+      .Run(unregistering_host_ ? START_ERROR : NETWORK_ERROR);
 }
 
 void HostStarter::OnHostUnregistered() {
@@ -227,9 +222,7 @@ void HostStarter::OnHostUnregistered() {
         &HostStarter::OnHostUnregistered, weak_ptr_));
     return;
   }
-  CompletionCallback cb = on_done_;
-  on_done_.Reset();
-  cb.Run(START_ERROR);
+  base::ResetAndReturn(&on_done_).Run(START_ERROR);
 }
 
 }  // namespace remoting
diff --git a/remoting/host/setup/oauth_client.cc b/remoting/host/setup/oauth_client.cc
index d96d360..fae8021 100644
--- a/remoting/host/setup/oauth_client.cc
+++ b/remoting/host/setup/oauth_client.cc
@@ -4,6 +4,7 @@
 
 #include "remoting/host/setup/oauth_client.h"
 
+#include "base/callback_helpers.h"
 #include "base/logging.h"
 
 namespace {
@@ -61,9 +62,7 @@ void OAuthClient::OnRefreshTokenResponse(
 
 void OAuthClient::SendResponse(const std::string& user_email,
                                const std::string& refresh_token) {
-  CompletionCallback on_done = on_done_;
-  on_done_.Reset();
-  on_done.Run(user_email, refresh_token);
+  base::ResetAndReturn(&on_done_).Run(user_email, refresh_token);
 
   // Process the next request in the queue.
   if (pending_requests_.size()) {