Unmute Tab Audio For Desktop Share

content/browser/media/capture/audio_mirroring_manager.h

Index: content/browser/media/capture/audio_mirroring_manager.h
diff --git a/content/browser/media/capture/audio_mirroring_manager.h b/content/browser/media/capture/audio_mirroring_manager.h
index a624a0824befa013d4868d12a3c75f50ac8417f6..dd1888ba964fbefce74e40c06917584b26267595 100644
--- a/content/browser/media/capture/audio_mirroring_manager.h
+++ b/content/browser/media/capture/audio_mirroring_manager.h
@@ -32,6 +32,7 @@
 #ifndef CONTENT_BROWSER_MEDIA_CAPTURE_AUDIO_MIRRORING_MANAGER_H_
 #define CONTENT_BROWSER_MEDIA_CAPTURE_AUDIO_MIRRORING_MANAGER_H_
 
+#include <map>
 #include <set>
 #include <utility>
 #include <vector>
@@ -41,6 +42,7 @@
 #include "base/threading/thread_checker.h"
 #include "content/common/content_export.h"
 #include "media/audio/audio_source_diverter.h"
+#include "media/audio/virtual_audio_sink.h"
 
 namespace media {
 class AudioOutputStream;
@@ -79,6 +81,11 @@ class CONTENT_EXPORT AudioMirroringManager {
     virtual media::AudioOutputStream* AddInput(
         const media::AudioParameters& params) = 0;
 
+    virtual media::AudioPushSink* AddPushInput(
+        const media::AudioParameters& params) = 0;
+
+    virtual bool IsDuplication() = 0;

[miu, 2016/04/21 00:15:24]

I was looking at how AudioMirroringManager uses this.  I think a lot of the
changes you made in the amm.cc could be made much simpler if you get rid of
this.  Instead, have the MatchesCallback (see line 71 above) include a second
boolean parameter that is true/false depending on whether it wants duplicated
audio.

The AudioMirroringManager is already rather complex.  In general, whenever
possible, try to limit its operations to one code path/sequence that works for
both the duplication vs. not duplication cases.

[qiangchen, 2016/04/28 00:00:56]

Done.

+
    protected:
     virtual ~MirroringDestination() {}
   };
@@ -120,6 +127,9 @@ class CONTENT_EXPORT AudioMirroringManager {
     // destination.
     MirroringDestination* destination;
 
+    // The destinations to which audio stream is duplicated.
+    std::map<MirroringDestination*, media::AudioPushSink*> dup_destinations;
+
     StreamRoutingState(const SourceFrameRef& source_frame,
                        Diverter* stream_diverter);
     StreamRoutingState(const StreamRoutingState& other);
@@ -143,6 +153,14 @@ class CONTENT_EXPORT AudioMirroringManager {
                                  bool add_only,
                                  const std::set<SourceFrameRef>& matches);
 
+  // MirroringDestination query callback.  |matches| contains all RenderFrame
+  // sources that will be duplicated to |destination|.  If |add_only| is false,
+  // then any Diverters currently duplicating to |destination| but not found in
+  // |matches| will be stopped.
+  void UpdateRoutesToDupDestination(MirroringDestination* destination,
+                                    bool add_only,
+                                    const std::set<SourceFrameRef>& matches);
+
   // Starts diverting audio to the |new_destination|, if not NULL.  Otherwise,
   // stops diverting audio.
   static void ChangeRoute(StreamRoutingState* route,