Unmute Tab Audio For Desktop Share

content/browser/media/capture/audio_mirroring_manager.cc

Index: content/browser/media/capture/audio_mirroring_manager.cc
diff --git a/content/browser/media/capture/audio_mirroring_manager.cc b/content/browser/media/capture/audio_mirroring_manager.cc
index f8b8b3a5b183e9d1b1ff07dd6728279b368d0c88..5de94815e15ce6718f33a1d5423033a6f1edc8e5 100644
--- a/content/browser/media/capture/audio_mirroring_manager.cc
+++ b/content/browser/media/capture/audio_mirroring_manager.cc
@@ -62,7 +62,13 @@ void AudioMirroringManager::RemoveDiverter(Diverter* diverter) {
   // diverted, it is stopped.
   for (StreamRoutes::iterator it = routes_.begin(); it != routes_.end(); ++it) {
     if (it->diverter == diverter) {
-      ChangeRoute(&(*it), NULL);
+      // Stop the diverted flow.
+      RouteDivertedFlow(&(*it), NULL);
+
+      // Stop duplication flows.
+      for (auto& dup : it->duplications) {
+        diverter->StopDuplicating(dup.second);
+      }
       routes_.erase(it);
       return;
     }
@@ -81,12 +87,12 @@ void AudioMirroringManager::StartMirroring(MirroringDestination* destination) {
     sessions_.push_back(destination);
   }
 
+  std::set<SourceFrameRef> candidates;
+
   // Query the MirroringDestination to see which of the audio streams should be
   // diverted.
-  std::set<SourceFrameRef> candidates;
   for (StreamRoutes::const_iterator it = routes_.begin(); it != routes_.end();
        ++it) {
-    if (!it->destination || it->destination == destination)
       candidates.insert(it->source_render_frame);
   }
   if (!candidates.empty()) {
@@ -108,9 +114,14 @@ void AudioMirroringManager::StopMirroring(MirroringDestination* destination) {
   std::set<SourceFrameRef> redivert_candidates;
   for (StreamRoutes::iterator it = routes_.begin(); it != routes_.end(); ++it) {
     if (it->destination == destination) {
-      ChangeRoute(&(*it), NULL);
+      RouteDivertedFlow(&(*it), NULL);
       redivert_candidates.insert(it->source_render_frame);
     }
+    auto dup_it = it->duplications.find(destination);
+    if (dup_it != it->duplications.end()) {
+      it->diverter->StopDuplicating(dup_it->second);
+      it->duplications.erase(dup_it);
+    }
   }
   if (!redivert_candidates.empty())
     InitiateQueriesToFindNewDestination(destination, redivert_candidates);
@@ -132,20 +143,30 @@ void AudioMirroringManager::InitiateQueriesToFindNewDestination(
 
   for (Destinations::const_iterator it = sessions_.begin();
        it != sessions_.end(); ++it) {
-    if (*it != old_destination) {
-      (*it)->QueryForMatches(
-          candidates,
-          base::Bind(&AudioMirroringManager::UpdateRoutesToDestination,
-                     base::Unretained(this),
-                     *it,
-                     true));
-    }
+    if (*it == old_destination)
+      continue;
+
+    (*it)->QueryForMatches(
+        candidates,
+        base::Bind(&AudioMirroringManager::UpdateRoutesToDestination,
+                   base::Unretained(this), *it, true));
   }
 }
 
 void AudioMirroringManager::UpdateRoutesToDestination(
     MirroringDestination* destination,
     bool add_only,
+    const std::set<SourceFrameRef>& matches,
+    bool is_duplicate) {
+  if (is_duplicate)
+    UpdateRoutesToDuplicateDestination(destination, add_only, matches);
+  else
+    UpdateRoutesToDivertDestination(destination, add_only, matches);
+}
+
+void AudioMirroringManager::UpdateRoutesToDivertDestination(
+    MirroringDestination* destination,
+    bool add_only,
     const std::set<SourceFrameRef>& matches) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
@@ -164,11 +185,11 @@ void AudioMirroringManager::UpdateRoutesToDestination(
     if (matches.find(it->source_render_frame) != matches.end()) {
       // Only change the route if the stream is not already being diverted.
       if (!it->destination)
-        ChangeRoute(&(*it), destination);
+        RouteDivertedFlow(&(*it), destination);
     } else if (!add_only) {
       // Only stop diverting if the stream is currently routed to |destination|.
       if (it->destination == destination) {
-        ChangeRoute(&(*it), NULL);
+        RouteDivertedFlow(&(*it), NULL);
         redivert_candidates.insert(it->source_render_frame);
       }
     }
@@ -177,9 +198,47 @@ void AudioMirroringManager::UpdateRoutesToDestination(
     InitiateQueriesToFindNewDestination(destination, redivert_candidates);
 }
 
+void AudioMirroringManager::UpdateRoutesToDuplicateDestination(
+    MirroringDestination* destination,
+    bool add_only,
+    const std::set<SourceFrameRef>& matches) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (std::find(sessions_.begin(), sessions_.end(), destination) ==
+      sessions_.end()) {
+    return;  // Query result callback invoked after StopMirroring().
+  }
+
+  for (StreamRoutes::iterator it = routes_.begin(); it != routes_.end(); ++it) {
+    if (matches.find(it->source_render_frame) != matches.end()) {
+      // The same destination cannot have both a diverted audio flow and a
+      // duplicated flow from the same source.
+      DCHECK_NE(it->destination, destination);
+
+      media::AudioPushSink*& pusher = it->duplications[destination];
+      if (!pusher) {
+        pusher = destination->AddPushInput(it->diverter->GetAudioParameters());
+        DCHECK(pusher);
+        it->diverter->StartDuplicating(pusher);
+      }
+    } else if (!add_only) {
+      auto dup_it = it->duplications.find(destination);
+      if (dup_it != it->duplications.end()) {
+        it->diverter->StopDuplicating(dup_it->second);
+        it->duplications.erase(dup_it);
+      }
+    }
+  }
+}
+
 // static
-void AudioMirroringManager::ChangeRoute(
-    StreamRoutingState* route, MirroringDestination* new_destination) {
+void AudioMirroringManager::RouteDivertedFlow(
+    StreamRoutingState* route,
+    MirroringDestination* new_destination) {
+  // The same destination cannot have both a diverted audio flow and a
+  // duplicated flow from the same source.
+  DCHECK(route->duplications.find(new_destination) ==
+         route->duplications.end());
+
   if (route->destination == new_destination)
     return;  // No change.