Bug 1286429 - Fire fake devicechange event in Camera IPC thread for mochitest; r=jib

MozReview-Commit-ID: 9sDLnMGh3xL

--HG--
extra : rebase_source : 026891d00450b9bfd792708ab3d5d2e730f431f9

dom/media/MediaManager.cpp

@@ -1709,6 +1709,7 @@ MediaManager::MediaManager()
   mPrefs.mNoiseOn      = false;
   mPrefs.mExtendedFilter = true;
   mPrefs.mDelayAgnostic = true;
+  mPrefs.mFakeDeviceChangeEventOn = false;
 #ifdef MOZ_WEBRTC
   mPrefs.mAec          = webrtc::kEcUnchanged;
   mPrefs.mAgc          = webrtc::kAgcUnchanged;
@@ -1807,6 +1808,7 @@ MediaManager::Get() {
       prefs->AddObserver("media.getusermedia.noise_enabled", sSingleton, false);
       prefs->AddObserver("media.getusermedia.noise", sSingleton, false);
       prefs->AddObserver("media.getusermedia.playout_delay", sSingleton, false);
+      prefs->AddObserver("media.ondevicechange.fakeDeviceChangeEvent.enabled", sSingleton, false);
 #endif
     }
 
@@ -1999,9 +2001,12 @@ bool MediaManager::IsPrivateBrowsing(nsPIDOMWindowInner* window)
 
 int MediaManager::AddDeviceChangeCallback(DeviceChangeCallback* aCallback)
 {
-  MediaManager::PostTask(NewTaskFrom([]() {
+  bool fakeDeviceChangeEventOn = mPrefs.mFakeDeviceChangeEventOn;
+  MediaManager::PostTask(NewTaskFrom([fakeDeviceChangeEventOn]() {
     RefPtr<MediaManager> manager = MediaManager_GetInstance();
     manager->GetBackend(0)->AddDeviceChangeCallback(manager);
+    if (fakeDeviceChangeEventOn)
+      manager->GetBackend(0)->SetFakeDeviceChangeEvents();
   }));
 
   return DeviceChangeCallback::AddDeviceChangeCallback(aCallback);
@@ -2875,6 +2880,7 @@ MediaManager::GetPrefs(nsIPrefBranch *aBranch, const char *aData)
   GetPref(aBranch, "media.getusermedia.playout_delay", aData, &mPrefs.mPlayoutDelay);
   GetPrefBool(aBranch, "media.getusermedia.aec_extended_filter", aData, &mPrefs.mExtendedFilter);
   GetPrefBool(aBranch, "media.getusermedia.aec_aec_delay_agnostic", aData, &mPrefs.mDelayAgnostic);
+  GetPrefBool(aBranch, "media.ondevicechange.fakeDeviceChangeEvent.enabled", aData, &mPrefs.mFakeDeviceChangeEventOn);
 #endif
   GetPrefBool(aBranch, "media.navigator.audio.full_duplex", aData, &mPrefs.mFullDuplex);
 }
@@ -2911,6 +2917,7 @@ MediaManager::Shutdown()
     prefs->RemoveObserver("media.getusermedia.noise_enabled", this);
     prefs->RemoveObserver("media.getusermedia.noise", this);
     prefs->RemoveObserver("media.getusermedia.playout_delay", this);
+    prefs->RemoveObserver("media.ondevicechange.fakeDeviceChangeEvent.enabled", this);
 #endif
     prefs->RemoveObserver("media.navigator.audio.full_duplex", this);
   }

dom/media/systemservices/CamerasChild.cpp

@@ -25,6 +25,9 @@ mozilla::LazyLogModule gCamerasChildLog("CamerasChild");
 #define LOG(args) MOZ_LOG(gCamerasChildLog, mozilla::LogLevel::Debug, args)
 #define LOG_ENABLED() MOZ_LOG_TEST(gCamerasChildLog, mozilla::LogLevel::Debug)
 
+#define FAKE_ONDEVICECHANGE_EVENT_PERIOD_IN_MS 5000
+#define FAKE_ONDEVICECHANGE_EVENT_REPEAT_COUNT 30
+
 namespace mozilla {
 namespace camera {
 
@@ -39,6 +42,34 @@ CamerasSingleton::~CamerasSingleton() {
   LOG(("~CamerasSingleton: %p", this));
 }
 
+class FakeOnDeviceChangeEventRunnable : public Runnable
+{
+public:
+  explicit FakeOnDeviceChangeEventRunnable(uint8_t counter)
+    : mCounter(counter) {}
+
+  NS_IMETHOD Run() override
+  {
+    OffTheBooksMutexAutoLock lock(CamerasSingleton::Mutex());
+
+    CamerasChild* child = CamerasSingleton::Child();
+    if (child) {
+      child->OnDeviceChange();
+
+      if (mCounter++ < FAKE_ONDEVICECHANGE_EVENT_REPEAT_COUNT) {
+        RefPtr<FakeOnDeviceChangeEventRunnable> evt = new FakeOnDeviceChangeEventRunnable(mCounter);
+        CamerasSingleton::Thread()->DelayedDispatch(evt.forget(),
+          FAKE_ONDEVICECHANGE_EVENT_PERIOD_IN_MS);
+      }
+    }
+
+    return NS_OK;
+  }
+
+private:
+  uint8_t mCounter;
+};
+
 class InitializeIPCThread : public Runnable
 {
 public:
@@ -592,6 +623,19 @@ CamerasChild::RecvDeviceChange()
   return true;
 }
 
+int
+CamerasChild::SetFakeDeviceChangeEvents()
+{
+  CamerasSingleton::Mutex().AssertCurrentThreadOwns();
+
+  // To simulate the devicechange event in mochitest,
+  // we fire a fake devicechange event in Camera IPC thread periodically
+  RefPtr<FakeOnDeviceChangeEventRunnable> evt = new FakeOnDeviceChangeEventRunnable(0);
+  CamerasSingleton::Thread()->Dispatch(evt.forget(), NS_DISPATCH_NORMAL);
+
+  return 0;
+}
+
 bool
 CamerasChild::RecvFrameSizeChange(const int& capEngine,
                                   const int& capId,

dom/media/systemservices/CamerasChild.h

@@ -160,6 +160,7 @@ public:
                                    const int& w, const int& h) override;
 
   virtual bool RecvDeviceChange() override;
+  int SetFakeDeviceChangeEvents();
 
   // these are response messages to our outgoing requests
   virtual bool RecvReplyNumberOfCaptureDevices(const int&) override;

dom/media/webrtc/MediaEngine.h

@@ -76,6 +76,8 @@ public:
 
   virtual void Shutdown() = 0;
 
+  virtual void SetFakeDeviceChangeEvents() {}
+
 protected:
   virtual ~MediaEngine() {}
 };
@@ -101,6 +103,7 @@ public:
     , mFullDuplex(false)
     , mExtendedFilter(false)
     , mDelayAgnostic(false)
+    , mFakeDeviceChangeEventOn(false)
   {}
 
   int32_t mWidth;
@@ -118,6 +121,7 @@ public:
   bool mFullDuplex;
   bool mExtendedFilter;
   bool mDelayAgnostic;
+  bool mFakeDeviceChangeEventOn;
 
   // mWidth and/or mHeight may be zero (=adaptive default), so use functions.
 

dom/media/webrtc/MediaEngineWebRTC.cpp

@@ -132,6 +132,13 @@ MediaEngineWebRTC::MediaEngineWebRTC(MediaEnginePrefs &aPrefs)
     this);
 }
 
+void
+MediaEngineWebRTC::SetFakeDeviceChangeEvents()
+{
+  camera::GetChildAndCall(
+    &camera::CamerasChild::SetFakeDeviceChangeEvents);
+}
+
 void
 MediaEngineWebRTC::EnumerateVideoDevices(dom::MediaSourceEnum aMediaSource,
                                          nsTArray<RefPtr<MediaEngineVideoSource> >* aVSources)

dom/media/webrtc/MediaEngineWebRTC.h

@@ -571,6 +571,8 @@ class MediaEngineWebRTC : public MediaEngine
 public:
   explicit MediaEngineWebRTC(MediaEnginePrefs& aPrefs);
 
+  virtual void SetFakeDeviceChangeEvents() override;
+
   // Clients should ensure to clean-up sources video/audio sources
   // before invoking Shutdown on this class.
   void Shutdown() override;

modules/libpref/init/all.js

@@ -4797,6 +4797,9 @@ pref("dom.imagecapture.enabled", false);
 // W3C MediaDevices devicechange event
 pref("media.ondevicechange.enabled", false);
 
+// W3C MediaDevices devicechange fake event
+pref("media.ondevicechange.fakeDeviceChangeEvent.enabled", false);
+
 // W3C touch-action css property (related to touch and pointer events)
 // Note that we turn this on even on platforms/configurations where touch
 // events are not supported (e.g. OS X, or Windows with e10s disabled). For