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..eb66f431b05f6ce5abb9d8c52ea9bdecdeafa24e 100644
--- a/content/browser/media/capture/audio_mirroring_manager.cc
+++ b/content/browser/media/capture/audio_mirroring_manager.cc
@@ -81,12 +81,12 @@ 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()) {
@@ -111,6 +111,11 @@ void AudioMirroringManager::StopMirroring(MirroringDestination* destination) {
       ChangeRoute(&(*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 +137,30 @@ 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());
 
@@ -177,6 +192,34 @@ 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()) {
+      media::AudioPushSink*& pusher = it->duplications[destination];

[miu, 2016/05/06 22:29:49]

Just before this line, please add a consistency check:

  // The same destination cannot have both a diverted audio flow and a
duplicated flow from the same source.
  DCHECK_NE(it->destination, destination);

[qiangchen, 2016/05/10 22:36:52]

Done.

+      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(

[miu, 2016/05/06 22:29:49]

To aid readability, could you change the name of this method to
RouteDivertedFlow()? (to make it clear this is about diverted flows and not
duplicated ones)

[qiangchen, 2016/05/10 22:36:52]

Done.

     StreamRoutingState* route, MirroringDestination* new_destination) {