Implementation of 'AudioContext.getOutputTimestamp' method

media/audio/audio_device_thread.h

Index: media/audio/audio_device_thread.h
diff --git a/media/audio/audio_device_thread.h b/media/audio/audio_device_thread.h
index f3287ef39ccf86705642dc5439f7b13860737f1d..e043f38e8930bedea05dfbb28e2785568384bd0c 100644
--- a/media/audio/audio_device_thread.h
+++ b/media/audio/audio_device_thread.h
@@ -12,10 +12,12 @@
 #include "base/sync_socket.h"
 #include "base/threading/platform_thread.h"
 #include "base/threading/thread_checker.h"
+#include "media/audio/audio_io.h"
 #include "media/base/audio_parameters.h"
 #include "media/base/media_export.h"
 
 namespace media {
+struct AudioTimestamp;
 
 // Data transfer between browser and render process uses a combination
 // of sync sockets and shared memory. To read from the socket and render
@@ -42,7 +44,9 @@ class MEDIA_EXPORT AudioDeviceThread : public base::PlatformThread::Delegate {
     virtual void MapSharedMemory() = 0;
 
     // Called whenever we receive notifications about pending input data.
-    virtual void Process(uint32_t pending_data) = 0;
+    // It also provides the current audio stream timestamp on the device.
+    virtual void Process(uint32_t pending_data,
+                         const AudioTimestamp& timestamp) = 0;
 
    protected:
     virtual ~Callback();
@@ -75,6 +79,12 @@ class MEDIA_EXPORT AudioDeviceThread : public base::PlatformThread::Delegate {
   // synchronous process and the thread will stop before the method returns.
   ~AudioDeviceThread() override;
 
+  // Represents a data packet to be received via the socket.
+  struct Packet {
+    uint32_t pending_data;
+    AudioTimestamp timestamp;
+  };
+
  private:
   void ThreadMain() final;