Basic use implementation for MediaStream from Canvas: captureStream()

third_party/WebKit/Source/core/html/HTMLCanvasElement.h

Index: third_party/WebKit/Source/core/html/HTMLCanvasElement.h
diff --git a/third_party/WebKit/Source/core/html/HTMLCanvasElement.h b/third_party/WebKit/Source/core/html/HTMLCanvasElement.h
index f208f37cd8c8b58d3b37059210374440d256c221..cbaf7f7eea3253656a400f425148c75179354500 100644
--- a/third_party/WebKit/Source/core/html/HTMLCanvasElement.h
+++ b/third_party/WebKit/Source/core/html/HTMLCanvasElement.h
@@ -36,6 +36,7 @@
 #include "core/dom/DocumentVisibilityObserver.h"
 #include "core/fileapi/FileCallback.h"
 #include "core/html/HTMLElement.h"
+#include "core/html/canvas/CanvasDrawListener.h"
 #include "core/html/canvas/CanvasImageSource.h"
 #include "core/imagebitmap/ImageBitmapSource.h"
 #include "platform/geometry/FloatRect.h"
@@ -61,7 +62,7 @@ class ImageBufferSurface;
 class ImageData;
 class IntSize;
 
-class CORE_EXPORT HTMLCanvasElement final : public HTMLElement, public DocumentVisibilityObserver, public CanvasImageSource, public ImageBufferClient, public ImageBitmapSource {
+class CORE_EXPORT HTMLCanvasElement : public HTMLElement, public DocumentVisibilityObserver, public CanvasImageSource, public ImageBufferClient, public ImageBitmapSource {

[esprehn, 2015/12/01 20:04:26]

why did you remove final?

[emircan, 2015/12/01 21:07:34]

modules/mediacapturefromelement/HTMLCanvasElementCapture extends it. Initially I
had HTMLCanvasElementCapture as STATIC_ONLY class but couldn't find a way around
adding ExceptionState. Is there a way around that?

     DEFINE_WRAPPERTYPEINFO();
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(HTMLCanvasElement);
 public:
@@ -102,6 +103,10 @@ public:
     void toBlob(FileCallback*, const String& mimeType, const ScriptValue& qualityArgument, ExceptionState&);
     void toBlob(FileCallback* callback, const String& mimeType, ExceptionState& exceptionState) { return toBlob(callback, mimeType, ScriptValue(), exceptionState); }
 
+    // Used for canvas capture.
+    void addListener(CanvasDrawListener*);
+    void removeListener(CanvasDrawListener*);
+
     // Used for rendering
     void didDraw(const FloatRect&);
 
@@ -198,9 +203,13 @@ private:
 
     bool paintsIntoCanvasBuffer() const;
 
+    void notifyListenersCanvasChanged();
+
     ImageData* toImageData(SourceDrawingBuffer) const;
     String toDataURLInternal(const String& mimeType, const double& quality, SourceDrawingBuffer) const;
 
+    PersistentHeapHashSetWillBeHeapHashSet<WeakMember<CanvasDrawListener>> m_listeners;
+
     IntSize m_size;
 
     OwnPtrWillBeMember<CanvasRenderingContext> m_context;