[Mojo Video Capture] Fix VideoCaptureManager exposing implementation details to clients

content/browser/renderer_host/media/media_stream_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/media_stream_manager.h"
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <algorithm>
@@ skipping 31 matching lines @@
 #include "content/public/browser/web_contents_media_capture_id.h"
 #include "content/public/common/content_client.h"
 #include "content/public/common/content_switches.h"
 #include "content/public/common/media_stream_request.h"
 #include "crypto/hmac.h"
 #include "media/audio/audio_device_description.h"
 #include "media/audio/audio_system.h"
 #include "media/base/audio_parameters.h"
 #include "media/base/channel_layout.h"
 #include "media/base/media_switches.h"
-#include "media/capture/video/video_capture_system.h"
+#include "media/capture/video/video_capture_device_factory.h"
+#include "media/capture/video/video_capture_system_impl.h"
 #include "url/gurl.h"
 #include "url/origin.h"
 
 #if defined(OS_WIN)
 #include "base/win/scoped_com_initializer.h"
 #endif
 
 #if defined(OS_CHROMEOS)
 #include "chromeos/audio/cras_audio_handler.h"
 #endif
@@ skipping 323 matching lines @@
   MediaStreamManager* msm = g_media_stream_manager_tls_ptr.Pointer()->Get();
   if (!msm) {
     DLOG(ERROR) << "No MediaStreamManager on the IO thread. " << message;
     return;
   }
 
   msm->AddLogMessageOnIOThread(message);
 }
 
 MediaStreamManager::MediaStreamManager(media::AudioSystem* audio_system)
+    : MediaStreamManager(audio_system, nullptr, nullptr) {}
+
+MediaStreamManager::MediaStreamManager(
+    media::AudioSystem* audio_system,
+    std::unique_ptr<media::VideoCaptureSystem> video_capture_system,
+    scoped_refptr<base::SingleThreadTaskRunner> device_task_runner)
     : audio_system_(audio_system),
 #if defined(OS_WIN)
       video_capture_thread_("VideoCaptureThread"),
 #endif
       use_fake_ui_(base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kUseFakeUIForMediaStream)) {
   DCHECK(audio_system_);
 
-  // Some unit tests create the MSM in the IO thread and assumes the
-  // initialization is done synchronously.
-  if (BrowserThread::CurrentlyOn(BrowserThread::IO)) {
-    InitializeDeviceManagersOnIOThread();
-  } else {
-    BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        base::Bind(&MediaStreamManager::InitializeDeviceManagersOnIOThread,
-                   base::Unretained(this)));
+  if (!video_capture_system) {
+    video_capture_system = base::MakeUnique<media::VideoCaptureSystemImpl>(
+        media::VideoCaptureDeviceFactory::CreateFactory(
+            BrowserThread::GetTaskRunnerForThread(BrowserThread::UI)));
   }
+  if (!device_task_runner) {
+    device_task_runner = audio_system_->GetTaskRunner();
+#if defined(OS_WIN)
+    // Use an STA Video Capture Thread to try to avoid crashes on enumeration of
+    // buggy third party Direct Show modules, http://crbug.com/428958.
+    video_capture_thread_.init_com_with_mta(false);
+    CHECK(video_capture_thread_.Start());
+    device_task_runner = video_capture_thread_.task_runner();
+#endif
+  }
+  InitializeMaybeAsync(std::move(video_capture_system),
+                       std::move(device_task_runner));
 
   base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
   // BrowserMainLoop always creates the PowerMonitor instance before creating
   // MediaStreamManager, but power_monitor may be NULL in unit tests.
   if (power_monitor)
     power_monitor->AddObserver(this);
 }
 
 MediaStreamManager::~MediaStreamManager() {
   DCHECK(!BrowserThread::IsThreadInitialized(BrowserThread::IO));
@@ skipping 783 matching lines @@
     const std::string& label,
     DeviceRequest* request,
     const MediaStreamDevices& devices) {
   if (!request->callback.is_null())
     request->callback.Run(devices, std::move(request->ui_proxy));
 
   // Delete the request since it is done.
   DeleteRequest(label);
 }
 
-void MediaStreamManager::InitializeDeviceManagersOnIOThread() {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+void MediaStreamManager::InitializeMaybeAsync(
+    std::unique_ptr<media::VideoCaptureSystem> video_capture_system,
+    scoped_refptr<base::SingleThreadTaskRunner> device_task_runner) {
+  // Some unit tests initialize the MSM in the IO thread and assume the
+  // initialization is done synchronously. Other clients call this from a
+  // different thread and expect initialization to run asynchronously.
+  if (!BrowserThread::CurrentlyOn(BrowserThread::IO)) {
+    BrowserThread::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(&MediaStreamManager::InitializeMaybeAsync,
+                   base::Unretained(this), base::Passed(&video_capture_system),
+                   std::move(device_task_runner)));
+    return;
+  }
+
   // Store a pointer to |this| on the IO thread to avoid having to jump to the
   // UI thread to fetch a pointer to the MSM. In particular on Android, it can
   // be problematic to post to a UI thread from arbitrary worker threads since
   // attaching to the VM is required and we may have to access the MSM from
   // callback threads that we don't own and don't want to attach.
   g_media_stream_manager_tls_ptr.Pointer()->Set(this);
 
   // TODO(dalecurtis): Remove ScopedTracker below once crbug.com/457525 is
   // fixed.
   tracked_objects::ScopedTracker tracking_profile1(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "457525 MediaStreamManager::InitializeDeviceManagersOnIOThread 1"));
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   // TODO(dalecurtis): Remove ScopedTracker below once crbug.com/457525 is
   // fixed.
   tracked_objects::ScopedTracker tracking_profile2(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "457525 MediaStreamManager::InitializeDeviceManagersOnIOThread 2"));
   audio_input_device_manager_ =
       new AudioInputDeviceManager(audio_system_->GetAudioManager());
   audio_input_device_manager_->RegisterListener(this);
 
   // TODO(dalecurtis): Remove ScopedTracker below once crbug.com/457525 is
   // fixed.
   tracked_objects::ScopedTracker tracking_profile3(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "457525 MediaStreamManager::InitializeDeviceManagersOnIOThread 3"));
   // We want to be notified of IO message loop destruction to delete the thread
   // and the device managers.
   base::MessageLoop::current()->AddDestructionObserver(this);
 
   // TODO(dalecurtis): Remove ScopedTracker below once crbug.com/457525 is
   // fixed.
   tracked_objects::ScopedTracker tracking_profile4(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "457525 MediaStreamManager::InitializeDeviceManagersOnIOThread 4"));
-  auto video_capture_system = base::MakeUnique<media::VideoCaptureSystem>(
-      media::VideoCaptureDeviceFactory::CreateFactory(
-          BrowserThread::GetTaskRunnerForThread(BrowserThread::UI)));
-#if defined(OS_WIN)
-  // Use an STA Video Capture Thread to try to avoid crashes on enumeration of
-  // buggy third party Direct Show modules, http://crbug.com/428958.
-  video_capture_thread_.init_com_with_mta(false);
-  CHECK(video_capture_thread_.Start());
+
   video_capture_manager_ = new VideoCaptureManager(
-      std::move(video_capture_system), video_capture_thread_.task_runner());
-#else
-  video_capture_manager_ = new VideoCaptureManager(
-      std::move(video_capture_system), audio_system_->GetTaskRunner());
-#endif
-
+      std::move(video_capture_system), std::move(device_task_runner));
   video_capture_manager_->RegisterListener(this);
 
   media_devices_manager_.reset(
       new MediaDevicesManager(audio_system_, video_capture_manager_, this));
 }
 
 void MediaStreamManager::Opened(MediaStreamType stream_type,
                                 int capture_session_id) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DVLOG(1) << "Opened({stream_type = " << stream_type <<  "} "
@@ skipping 480 matching lines @@
     request->ui_proxy->OnStarted(
         base::Bind(&MediaStreamManager::StopMediaStreamFromBrowser,
                    base::Unretained(this), label),
         base::Bind(&MediaStreamManager::OnMediaStreamUIWindowId,
                    base::Unretained(this), request->video_type(),
                    request->devices));
   }
 }
 
 }  // namespace content