[CodeHealth] Convert c/b/e/api/braille_display_private to use modern callback

Note: |connection_| in BrailleControllerImpl never reset and
CreateBrlapiConnectionFunction never returns nullptr, thus OnceCallback
can be used.

Bug: 1152279
Change-Id: I3a7044c7b4143698fb363aa5a4a694156754a0df
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2640537Reviewed-by: Finnur Thorarinsson <finnur@chromium.org>
Commit-Queue: Maksim Moskvitin <mmoskvitin@google.com>
Cr-Commit-Position: refs/heads/master@{#845678}

chrome/browser/extensions/api/braille_display_private/braille_controller_brlapi.cc

@@ -55,9 +55,8 @@ BrailleControllerImpl* BrailleControllerImpl::GetInstance() {
 }
 
 BrailleControllerImpl::BrailleControllerImpl() {
-  create_brlapi_connection_function_ = base::Bind(
-      &BrailleControllerImpl::CreateBrlapiConnection,
-      base::Unretained(this));
+  create_brlapi_connection_function_ = base::BindOnce(
+      &BrailleControllerImpl::CreateBrlapiConnection, base::Unretained(this));
 }
 
 BrailleControllerImpl::~BrailleControllerImpl() = default;
@@ -141,13 +140,12 @@ void BrailleControllerImpl::RemoveObserver(BrailleObserver* observer) {
 }
 
 void BrailleControllerImpl::SetCreateBrlapiConnectionForTesting(
-    const CreateBrlapiConnectionFunction& function) {
+    CreateBrlapiConnectionFunction function) {
   if (function.is_null()) {
-    create_brlapi_connection_function_ = base::Bind(
-        &BrailleControllerImpl::CreateBrlapiConnection,
-        base::Unretained(this));
+    create_brlapi_connection_function_ = base::BindOnce(
+        &BrailleControllerImpl::CreateBrlapiConnection, base::Unretained(this));
   } else {
-    create_brlapi_connection_function_ = function;
+    create_brlapi_connection_function_ = std::move(function);
   }
 }
 
@@ -190,7 +188,8 @@ void BrailleControllerImpl::StartWatchingSocketDirOnTaskThread() {
   base::FilePath brlapi_dir(BRLAPI_SOCKETPATH);
   if (!file_path_watcher_.Watch(
           brlapi_dir, base::FilePathWatcher::Type::kNonRecursive,
-          base::Bind(&BrailleControllerImpl::OnSocketDirChangedOnTaskThread,
+          base::BindRepeating(
+              &BrailleControllerImpl::OnSocketDirChangedOnTaskThread,
               base::Unretained(this)))) {
     LOG(WARNING) << "Couldn't watch brlapi directory " << BRLAPI_SOCKETPATH;
   }
@@ -225,13 +224,17 @@ void BrailleControllerImpl::TryToConnect() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(skip_libbrlapi_so_load_ || libbrlapi_loader_.loaded());
   connect_scheduled_ = false;
-  if (!connection_.get())
-    connection_ = create_brlapi_connection_function_.Run();
-  if (connection_.get() && !connection_->Connected()) {
+  if (!connection_.get()) {
+    DCHECK(!create_brlapi_connection_function_.is_null());
+    connection_ = std::move(create_brlapi_connection_function_).Run();
+  }
+
+  DCHECK(connection_);
+  if (!connection_->Connected()) {
     VLOG(1) << "Trying to connect to brlapi";
-    BrlapiConnection::ConnectResult result = connection_->Connect(base::Bind(
-        &BrailleControllerImpl::DispatchKeys,
-        base::Unretained(this)));
+    BrlapiConnection::ConnectResult result =
+        connection_->Connect(base::BindRepeating(
+            &BrailleControllerImpl::DispatchKeys, base::Unretained(this)));
     switch (result) {
       case BrlapiConnection::CONNECT_SUCCESS:
         DispatchOnDisplayStateChanged(GetDisplayState());

chrome/browser/extensions/api/braille_display_private/braille_controller_brlapi.h

@@ -8,6 +8,7 @@
 #include <memory>
 #include <vector>
 
+#include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "base/files/file_path_watcher.h"
 #include "base/memory/singleton.h"
@@ -42,13 +43,13 @@ class BrailleControllerImpl : public BrailleController {
   ~BrailleControllerImpl() override;
   void TryLoadLibBrlApi();
 
-  typedef base::Callback<std::unique_ptr<BrlapiConnection>()>
-      CreateBrlapiConnectionFunction;
+  using CreateBrlapiConnectionFunction =
+      base::OnceCallback<std::unique_ptr<BrlapiConnection>()>;
 
   // For dependency injection in tests.  Sets the function used to create
   // brlapi connections.
   void SetCreateBrlapiConnectionForTesting(
-      const CreateBrlapiConnectionFunction& callback);
+      CreateBrlapiConnectionFunction callback);
 
   // Makes the controller try to reconnect (if disconnected) as if the brlapi
   // socket directory had changed.

chrome/browser/extensions/api/braille_display_private/braille_display_private_apitest.cc

@@ -65,9 +65,10 @@ class MockBrlapiConnection : public BrlapiConnection {
  public:
   explicit MockBrlapiConnection(MockBrlapiConnectionData* data)
       : data_(data) {}
-  ConnectResult Connect(const OnDataReadyCallback& on_data_ready) override {
+
+  ConnectResult Connect(OnDataReadyCallback on_data_ready) override {
     data_->connected = true;
-    on_data_ready_ = on_data_ready;
+    on_data_ready_ = std::move(on_data_ready);
     if (!data_->pending_keys.empty()) {
       content::GetIOThreadTaskRunner({})->PostTask(
           FROM_HERE, base::BindOnce(&MockBrlapiConnection::NotifyDataReady,
@@ -154,8 +155,7 @@ class BrailleDisplayPrivateApiTest : public ExtensionApiTest {
     connection_data_.error.brlerrno = BRLAPI_ERROR_SUCCESS;
     connection_data_.reappear_on_disconnect = false;
     BrailleControllerImpl::GetInstance()->SetCreateBrlapiConnectionForTesting(
-        base::Bind(
-            &BrailleDisplayPrivateApiTest::CreateBrlapiConnection,
+        base::BindOnce(&BrailleDisplayPrivateApiTest::CreateBrlapiConnection,
                        base::Unretained(this)));
     BrailleControllerImpl::GetInstance()->skip_libbrlapi_so_load_ = true;
     DisableAccessibilityManagerBraille();

chrome/browser/extensions/api/braille_display_private/brlapi_connection.cc

@@ -41,7 +41,7 @@ class BrlapiConnectionImpl : public BrlapiConnection {
   BrlapiConnectionImpl& operator=(const BrlapiConnectionImpl&) = delete;
   ~BrlapiConnectionImpl() override { Disconnect(); }
 
-  ConnectResult Connect(const OnDataReadyCallback& on_data_ready) override;
+  ConnectResult Connect(OnDataReadyCallback on_data_ready) override;
   void Disconnect() override;
   bool Connected() override { return handle_ != nullptr; }
   brlapi_error_t* BrlapiError() override;
@@ -67,7 +67,7 @@ std::unique_ptr<BrlapiConnection> BrlapiConnection::Create(
 }
 
 BrlapiConnection::ConnectResult BrlapiConnectionImpl::Connect(
-    const OnDataReadyCallback& on_data_ready) {
+    OnDataReadyCallback on_data_ready) {
   DCHECK(!handle_);
   handle_.reset(reinterpret_cast<brlapi_handle_t*>(
       malloc(libbrlapi_loader_->brlapi_getHandleSize())));
@@ -125,7 +125,7 @@ BrlapiConnection::ConnectResult BrlapiConnectionImpl::Connect(
   }
 
   fd_controller_ =
-      base::FileDescriptorWatcher::WatchReadable(fd, on_data_ready);
+      base::FileDescriptorWatcher::WatchReadable(fd, std::move(on_data_ready));
 
   return CONNECT_SUCCESS;
 }

chrome/browser/extensions/api/braille_display_private/brlapi_connection.h

@@ -21,7 +21,7 @@ namespace braille_display_private {
 // about the semantics of the methods in this class.
 class BrlapiConnection {
  public:
-  typedef base::Closure OnDataReadyCallback;
+  typedef base::RepeatingClosure OnDataReadyCallback;
 
   enum ConnectResult {
     CONNECT_ERROR_RETRY,
@@ -35,7 +35,7 @@ class BrlapiConnection {
   BrlapiConnection& operator=(const BrlapiConnection&) = delete;
   virtual ~BrlapiConnection() = default;
 
-  virtual ConnectResult Connect(const OnDataReadyCallback& onDataReady) = 0;
+  virtual ConnectResult Connect(OnDataReadyCallback onDataReady) = 0;
 
   virtual void Disconnect() = 0;