Implement permission_broker for serial devices.

device/serial/serial_io_handler.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "device/serial/serial_io_handler.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 
 namespace device {
 
 SerialIoHandler::SerialIoHandler(
-    scoped_refptr<base::MessageLoopProxy> file_thread_message_loop)
-    : file_thread_message_loop_(file_thread_message_loop) {
+    scoped_refptr<base::MessageLoopProxy> file_thread_message_loop,
+    scoped_refptr<base::MessageLoopProxy> ui_thread_message_loop)
+    : file_thread_message_loop_(file_thread_message_loop),
+      ui_thread_message_loop_(ui_thread_message_loop) {
 }
 
 SerialIoHandler::~SerialIoHandler() {
   DCHECK(CalledOnValidThread());
   Close();
 }
 
 void SerialIoHandler::Open(const std::string& port,
                            const OpenCompleteCallback& callback) {
   DCHECK(CalledOnValidThread());
   DCHECK(open_complete_.is_null());
   open_complete_ = callback;
   DCHECK(file_thread_message_loop_.get());
-  file_thread_message_loop_->PostTask(
-      FROM_HERE,
-      base::Bind(&SerialIoHandler::StartOpen,
-                 this,
-                 port,
-                 base::MessageLoopProxy::current()));
+  DCHECK(ui_thread_message_loop_.get());
+  RequestAccess(port, file_thread_message_loop_, ui_thread_message_loop_);
+}
+
+void SerialIoHandler::RequestAccess(
+    const std::string& port,
+    scoped_refptr<base::MessageLoopProxy> file_message_loop,
+    scoped_refptr<base::MessageLoopProxy> ui_message_loop) {

[Reilly Grant (use Gerrit), 2014/10/15 00:33:02]

Why pass these as parameters when they are available as object members in the
function below?

[Jorge Lucangeli Obes, 2014/10/15 00:35:58]

Because they're private members and need to be accessed by RequestAccess in
SerialIoHandlerPosix (to post to the UI thread), which is a subclass.

I could also add accessors, like what's done for file().

+  OnRequestAccessComplete(port, true /* success */);
+}
+
+void SerialIoHandler::OnRequestAccessComplete(const std::string& port,
+                                              bool success) {
+  DCHECK(CalledOnValidThread());
+  if (success) {
+    DCHECK(file_thread_message_loop_.get());
+    file_thread_message_loop_->PostTask(
+        FROM_HERE,
+        base::Bind(&SerialIoHandler::StartOpen,
+                   this,
+                   port,
+                   base::MessageLoopProxy::current()));
+    return;
+  } else {
+    DCHECK(!open_complete_.is_null());
+    OpenCompleteCallback callback = open_complete_;
+    open_complete_.Reset();
+    callback.Run(false);
+    return;
+  }
 }
 
 void SerialIoHandler::StartOpen(
     const std::string& port,
     scoped_refptr<base::MessageLoopProxy> io_message_loop) {
   DCHECK(!open_complete_.is_null());
   DCHECK(file_thread_message_loop_->RunsTasksOnCurrentThread());
   DCHECK(!file_.IsValid());
   // It's the responsibility of the API wrapper around SerialIoHandler to
   // validate the supplied path against the set of valid port names, and
@@ skipping 127 matching lines @@
 }
 
 void SerialIoHandler::QueueWriteCompleted(int bytes_written,
                                           serial::SendError error) {
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&SerialIoHandler::WriteCompleted, this, bytes_written, error));
 }
 
 }  // namespace device