Decouple capture timestamp and reference time

media/capture/video/win/sink_input_pin_win.cc

Index: media/capture/video/win/sink_input_pin_win.cc
diff --git a/media/capture/video/win/sink_input_pin_win.cc b/media/capture/video/win/sink_input_pin_win.cc
index d376dde89962a784c048e20283733615f02d7a9f..b29215829de817b3ecdd036c6e8faa072e7ff054 100644
--- a/media/capture/video/win/sink_input_pin_win.cc
+++ b/media/capture/video/win/sink_input_pin_win.cc
@@ -13,6 +13,7 @@
 
 #include "base/logging.h"
 #include "base/macros.h"
+#include "media/base/timestamp_constants.h"
 
 namespace media {
 
@@ -201,15 +202,12 @@ HRESULT SinkInputPin::Receive(IMediaSample* sample) {
     return S_FALSE;
 
   REFERENCE_TIME start_time, end_time;
-  base::TimeTicks timestamp;
+  base::TimeDelta timestamp = media::kNoTimestamp();
   if (SUCCEEDED(sample->GetTime(&start_time, &end_time))) {
     DCHECK(start_time <= end_time);
-    timestamp += base::TimeDelta::FromMicroseconds(start_time / 10);
-  } else {
-    timestamp = base::TimeTicks::Now();
+    timestamp = base::TimeDelta::FromMicroseconds(start_time / 10);
   }
 
-
   observer_->FrameReceived(buffer, length, timestamp);
   return S_OK;
 }