Add TimedCanvasDrawListener

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

Index: third_party/WebKit/Source/modules/mediacapturefromelement/TimedCanvasDrawListener.cpp
diff --git a/third_party/WebKit/Source/modules/mediacapturefromelement/TimedCanvasDrawListener.cpp b/third_party/WebKit/Source/modules/mediacapturefromelement/TimedCanvasDrawListener.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..0850ad47a5357da61472c3fdfaa700f7cf9e2aab
--- /dev/null
+++ b/third_party/WebKit/Source/modules/mediacapturefromelement/TimedCanvasDrawListener.cpp
@@ -0,0 +1,48 @@
+// 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 "config.h"
+#include "modules/mediacapturefromelement/TimedCanvasDrawListener.h"
+
+#include "platform/Task.h"
+#include "public/platform/Platform.h"
+#include "public/platform/WebSkImage.h"
+#include "public/platform/WebTaskRunner.h"
+#include "public/platform/WebTraceLocation.h"
+
+namespace blink {
+
+TimedCanvasDrawListener::TimedCanvasDrawListener(const PassOwnPtr<WebCanvasCaptureHandler>& handler, double frameRate)
+    : CanvasDrawListener(handler)
+{
+    m_frameInterval = 1000 / frameRate;
+    requestNewFrame();

[esprehn, 2015/12/15 23:58:01]

can we do this in the caller? The constructor having side effects is a little
sad.

[emircan, 2015/12/16 15:36:21]

Done.

+}
+
+TimedCanvasDrawListener::~TimedCanvasDrawListener() {}
+
+// static
+TimedCanvasDrawListener* TimedCanvasDrawListener::create(const PassOwnPtr<WebCanvasCaptureHandler>& handler, double frameRate)
+{
+    return new TimedCanvasDrawListener(handler, frameRate);
+}
+
+bool TimedCanvasDrawListener::needsNewFrame() const
+{
+    return m_requestFrame && CanvasDrawListener::needsNewFrame();
+}
+
+void TimedCanvasDrawListener::sendNewFrame(const WTF::PassRefPtr<SkImage>& image)
+{
+    m_requestFrame = false;
+    CanvasDrawListener::sendNewFrame(image);
+}
+
+void TimedCanvasDrawListener::requestNewFrame()
+{
+    m_requestFrame = true;
+    Platform::current()->currentThread()->taskRunner()->postDelayedTask(BLINK_FROM_HERE, new Task(bind(&TimedCanvasDrawListener::requestNewFrame, this)), m_frameInterval);
+}
+
+} // namespace blink