Canvas captureStream() to capture a frame in the start

third_party/WebKit/Source/modules/mediacapturefromelement/CanvasCaptureMediaStreamTrack.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/mediacapturefromelement/CanvasCaptureMediaStreamTrack.h"
 
 #include "core/html/HTMLCanvasElement.h"
 #include "modules/mediacapturefromelement/AutoCanvasDrawListener.h"
 #include "modules/mediacapturefromelement/OnRequestCanvasDrawListener.h"
 #include "modules/mediacapturefromelement/TimedCanvasDrawListener.h"
@@ skipping 55 matching lines @@
     m_canvasElement->addListener(m_drawListener.get());
 }
 
 CanvasCaptureMediaStreamTrack::CanvasCaptureMediaStreamTrack(MediaStreamComponent* component, PassRefPtrWillBeRawPtr<HTMLCanvasElement> element, const PassOwnPtr<WebCanvasCaptureHandler> handler, double frameRate)
     : MediaStreamTrack(element->executionContext(), component)
     , m_canvasElement(element)
 {
     suspendIfNeeded();
     if (frameRate == 0) {
         m_drawListener = OnRequestCanvasDrawListener::create(handler);
+        m_drawListener->requestFrame();
     } else {
         TimedCanvasDrawListener* listener = TimedCanvasDrawListener::create(handler, frameRate);
         listener->requestNewFrame();
         m_drawListener = listener;
     }
     m_canvasElement->addListener(m_drawListener.get());
 }
 
 } // namespace blink