Added automatic mode to FakeInputAudioStream to generate automatic beeps

content/browser/renderer_host/media/audio_input_device_manager.cc

 // Copyright (c) 2012 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 "content/browser/renderer_host/media/audio_input_device_manager.h"
 
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/common/media_stream_request.h"
 #include "media/audio/audio_device_name.h"
 #include "media/audio/audio_input_ipc.h"
 #include "media/audio/audio_manager_base.h"
 #include "media/audio/audio_parameters.h"
 #include "media/base/channel_layout.h"
 #include "media/base/scoped_histogram_timer.h"
 
 namespace content {
 
 const int AudioInputDeviceManager::kFakeOpenSessionId = 1;
 
+const char kFakeDeviceName[] = "Fake Audio";
+const char kFakeDeviceId[] = "fake_audio";
+
 namespace {
 // Starting id for the first capture session.
 const int kFirstSessionId = AudioInputDeviceManager::kFakeOpenSessionId + 1;
 }
 
 AudioInputDeviceManager::AudioInputDeviceManager(
     media::AudioManager* audio_manager)
     : listener_(NULL),
       next_capture_session_id_(kFirstSessionId),
       use_fake_device_(false),
       audio_manager_(audio_manager) {
   // TODO(xians): Remove this fake_device after the unittests do not need it.
   StreamDeviceInfo fake_device(MEDIA_DEVICE_AUDIO_CAPTURE,
-                               media::AudioManagerBase::kDefaultDeviceName,
-                               media::AudioManagerBase::kDefaultDeviceId,
+                               kFakeDeviceName,
+                               kFakeDeviceName,

[DaleCurtis, 2014/04/29 17:33:31]

FakeDeviceId?

[no longer working on chromium, 2014/05/02 14:30:47]

Done.

                                44100, media::CHANNEL_LAYOUT_STEREO,
                                0);
   fake_device.session_id = kFakeOpenSessionId;
   devices_.push_back(fake_device);
 }
 
 AudioInputDeviceManager::~AudioInputDeviceManager() {
 }
 
 const StreamDeviceInfo* AudioInputDeviceManager::GetOpenedDeviceInfoById(
@@ skipping 85 matching lines @@
       // BrowserMainloop.
       audio_manager_->GetAudioInputDeviceNames(&device_names);
       break;
 
     default:
       NOTREACHED();
       break;
   }
 
   scoped_ptr<StreamDeviceInfoArray> devices(new StreamDeviceInfoArray());
-  for (media::AudioDeviceNames::iterator it = device_names.begin();
-       it != device_names.end(); ++it) {
-    // Add device information to device vector.
-    devices->push_back(StreamDeviceInfo(
-        stream_type, it->device_name, it->unique_id));
-  }
-
-  // If the |use_fake_device_| flag is on, inject the fake device if there is
-  // no available device on the OS.
-  if (use_fake_device_ && devices->empty()) {
-    devices->push_back(StreamDeviceInfo(
-        stream_type, media::AudioManagerBase::kDefaultDeviceName,
-        media::AudioManagerBase::kDefaultDeviceId));
+  // If the |use_fake_device_| flag is on or there is no available device on
+  // the OS, inject the fake device.
+  if (use_fake_device_ || devices->empty()) {

[DaleCurtis, 2014/04/29 17:33:31]

Won't devices() always be empty()? You're constructing it right here.

[phoglund_chromium, 2014/04/30 08:03:49]

Yeah, looks like the else branch will never be taken. You probably want to check
if device_names is empty.

[no longer working on chromium, 2014/05/02 14:30:47]

Ah, right, I just missed that devices were different from device_names. That
might be why lots of unittests failed, I looked deeper at those tests, it seems
that they mocked out the AudioManager and injected fake devices in the
enumeration APIs.
So I just fall back to the previous behavior and only inject the fake device if
the use_fake_device is true and there is no enumerated device.

[no longer working on chromium, 2014/05/02 14:30:47]

That was what I was thinking but realized that it would inject a fake device in
production when the list is empty, which is un-wanted change. Also some
unittests mocked out the AudioManager and injected fake devices in the
enumeration APIs. There is no easy way to change them to use
AudioInputDeviceManager().
So I just fall back to the previous behavior and only inject the fake device if
the use_fake_device is true and there is no enumerated device.

+    devices->push_back(StreamDeviceInfo(stream_type, kFakeDeviceName,
+                                        kFakeDeviceId));
+  } else {
+    for (media::AudioDeviceNames::iterator it = device_names.begin();
+         it != device_names.end(); ++it) {
+      // Add device information to device vector.
+      devices->push_back(StreamDeviceInfo(
+          stream_type, it->device_name, it->unique_id));
+    }

[DaleCurtis, 2014/04/29 17:33:31]

You're no longer injecting a fake device if no device is present.  Is this
intended?

[no longer working on chromium, 2014/05/02 14:30:47]

We don't inject the fake device in production. The previous code only inject the
fake device when use_fake_device_ is true (which is always false in production)
and devices->empty().

   }
 
   // Return the device list through the listener by posting a task on
   // IO thread since MediaStreamManager handles the callback asynchronously.
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
       base::Bind(&AudioInputDeviceManager::DevicesEnumeratedOnIOThread,
                  this, stream_type, base::Passed(&devices)));
 }
@@ skipping 84 matching lines @@
   for (StreamDeviceList::iterator i(devices_.begin()); i != devices_.end();
        ++i) {
     if (i->session_id == session_id)
       return i;
   }
 
   return devices_.end();
 }
 
 }  // namespace content