Fix getUserMedia so that failure is reported for invalid audio sources.

content/renderer/media/user_media_client_impl.h

Index: content/renderer/media/user_media_client_impl.h
diff --git a/content/renderer/media/user_media_client_impl.h b/content/renderer/media/user_media_client_impl.h
index 2492ccc00bebd8fc887990a2b46527f765a0e549..eebd327d3bd547e45a6e4422eb2656d1a082c8c3 100644
--- a/content/renderer/media/user_media_client_impl.h
+++ b/content/renderer/media/user_media_client_impl.h
@@ -119,7 +119,8 @@ class CONTENT_EXPORT UserMediaClientImpl
   // These are virtual for test purposes.
   virtual MediaStreamAudioSource* CreateAudioSource(
       const StreamDeviceInfo& device,
-      const blink::WebMediaConstraints& constraints);
+      const blink::WebMediaConstraints& constraints,
+      const MediaStreamSource::ConstraintsCallback& source_ready);
   virtual MediaStreamVideoSource* CreateVideoSource(
       const StreamDeviceInfo& device,
       const MediaStreamSource::SourceStoppedCallback& stop_callback);
@@ -146,7 +147,8 @@ class CONTENT_EXPORT UserMediaClientImpl
     blink::WebMediaStream web_stream;
     blink::WebUserMediaRequest request;
 
-    void StartAudioTrack(const blink::WebMediaStreamTrack& track);
+    void StartAudioTrack(const blink::WebMediaStreamTrack& track,
+                         bool source_initialized);
 
     blink::WebMediaStreamTrack CreateAndStartVideoTrack(
         const blink::WebMediaStreamSource& source,
@@ -156,16 +158,22 @@ class CONTENT_EXPORT UserMediaClientImpl
     // successfully started, or a source has failed to start.
     void CallbackOnTracksStarted(const ResourcesReady& callback);
 
-    bool IsSourceUsed(const blink::WebMediaStreamSource& source) const;
-    void RemoveSource(const blink::WebMediaStreamSource& source);
-
     bool HasPendingSources() const;
 
+    // Called when a local audio source has finished (or failed) initializing.
+    void OnAudioSourceStarted(MediaStreamSource* source,
+                              MediaStreamRequestResult result,
+                              const blink::WebString& result_name);
+
    private:
     void OnTrackStarted(
         MediaStreamSource* source,
         MediaStreamRequestResult result,
         const blink::WebString& result_name);
+
+    // Cheks if the sources for all tracks have been started and if so,
+    // invoke the |ready_callback_|.  Note that the caller should expect
+    // that |this| might be deleted when the function returns.
     void CheckAllTracksStarted();
 
     ResourcesReady ready_callback_;
@@ -193,12 +201,17 @@ class CONTENT_EXPORT UserMediaClientImpl
 
   // Creates a WebKit representation of stream sources based on
   // |devices| from the MediaStreamDispatcher.
-  void InitializeSourceObject(
+  void InitializeVideoSourceObject(
       const StreamDeviceInfo& device,
-      blink::WebMediaStreamSource::Type type,
       const blink::WebMediaConstraints& constraints,
       blink::WebMediaStreamSource* webkit_source);
 
+  void InitializeAudioSourceObject(

[miu, 2017/01/11 20:51:11]

Please return a bool instead of make the caller provide a separate output
argument. (Discussed further in .cc file comments.) Also, suggest you use
WARN_UNUSED_RESULT to make sure code acts on this bool.

[tommi (sloooow) - chröme, 2017/01/11 22:40:59]

Done.  Also changed InitializeVideoSourceObject to follow the same convention.

However, I can't return bool since that would indicate whether or not the
function failed to do its job. I realize this is a misunderstanding because I
chose a poor variable name for |source_initialized|.  Instead I've renamed that
variable to |is_pending| and reversed how it's used.

+      const StreamDeviceInfo& device,
+      const blink::WebMediaConstraints& constraints,
+      blink::WebMediaStreamSource* webkit_source,
+      bool* source_initialized);
+
   void CreateVideoTracks(
       const StreamDeviceInfoArray& devices,
       const blink::WebMediaConstraints& constraints,
@@ -222,6 +235,17 @@ class CONTENT_EXPORT UserMediaClientImpl
       const StreamDeviceInfoArray& audio_array,
       const StreamDeviceInfoArray& video_array);
 
+  static void OnAudioSourceStartedOnAudioThread(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+      base::WeakPtr<UserMediaClientImpl> weak_ptr,
+      MediaStreamSource* source,
+      MediaStreamRequestResult result,
+      const blink::WebString& result_name);
+
+  void OnAudioSourceStarted(MediaStreamSource* source,
+                            MediaStreamRequestResult result,
+                            const blink::WebString& result_name);
+
   using EnumerationResult = std::vector<MediaDeviceInfoArray>;
   void FinalizeEnumerateDevices(blink::WebMediaDevicesRequest request,
                                 const EnumerationResult& result);
@@ -231,8 +255,22 @@ class CONTENT_EXPORT UserMediaClientImpl
   // Returns the source that use a device with |device.session_id|
   // and |device.device.id|. NULL if such source doesn't exist.
   const blink::WebMediaStreamSource* FindLocalSource(
+      const StreamDeviceInfo& device) const {
+    return FindLocalSource(local_sources_, device);
+  }
+  const blink::WebMediaStreamSource* FindPendingLocalSource(
+      const StreamDeviceInfo& device) const {
+    return FindLocalSource(pending_local_sources_, device);
+  }
+  const blink::WebMediaStreamSource* FindLocalSource(
+      const LocalStreamSources& sources,
       const StreamDeviceInfo& device) const;
 
+  // Looks up a local source and returns it if found. If not found, prepares
+  // a new WebMediaStreamSource with a NULL extraData pointer.
+  blink::WebMediaStreamSource FindOrInitializeSourceObject(
+      const StreamDeviceInfo& device);
+
   // Returns true if we do find and remove the |source|.
   // Otherwise returns false.
   bool RemoveLocalSource(const blink::WebMediaStreamSource& source);
@@ -274,6 +312,7 @@ class CONTENT_EXPORT UserMediaClientImpl
   ::mojom::MediaDevicesDispatcherHostPtr media_devices_dispatcher_;
 
   LocalStreamSources local_sources_;
+  LocalStreamSources pending_local_sources_;
 
   UserMediaRequests user_media_requests_;
   MediaDevicesEventDispatcher::SubscriptionIdList