2D Canvas doesn't blend video with the destination buffer.

content/renderer/media/webmediaplayer_ms.cc

 // Copyright 2013 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 "content/renderer/media/webmediaplayer_ms.h"
 
 #include <limits>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 298 matching lines @@
 double WebMediaPlayerMS::maxTimeSeekable() const {
   DCHECK(thread_checker_.CalledOnValidThread());
   return 0.0;
 }
 
 bool WebMediaPlayerMS::didLoadingProgress() {
   DCHECK(thread_checker_.CalledOnValidThread());
   return true;
 }
 
-void WebMediaPlayerMS::paint(WebCanvas* canvas,
-                             const WebRect& rect,
+void WebMediaPlayerMS::paint(blink::WebCanvas* canvas,
+                             const blink::WebRect& rect,
                              unsigned char alpha) {
+  paint(canvas, rect, alpha, SkXfermode::kSrcOver_Mode);
+}
+
+void WebMediaPlayerMS::paint(blink::WebCanvas* canvas,
+                             const blink::WebRect& rect,
+                             unsigned char alpha,
+                             SkXfermode::Mode mode) {
   DVLOG(3) << "WebMediaPlayerMS::paint";
   DCHECK(thread_checker_.CalledOnValidThread());
 
   gfx::RectF dest_rect(rect.x, rect.y, rect.width, rect.height);
-  video_renderer_.Paint(current_frame_.get(), canvas, dest_rect, alpha);
+  video_renderer_.Paint(current_frame_.get(),
+                        canvas,
+                        dest_rect,
+                        alpha,
+                        mode);
 
   {
     base::AutoLock auto_lock(current_frame_lock_);
     if (current_frame_.get())
       current_frame_used_ = true;
   }
 }
 
 bool WebMediaPlayerMS::hasSingleSecurityOrigin() const {
   DCHECK(thread_checker_.CalledOnValidThread());
@@ skipping 132 matching lines @@
   GetClient()->readyStateChanged();
 }
 
 blink::WebMediaPlayerClient* WebMediaPlayerMS::GetClient() {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(client_);
   return client_;
 }
 
 }  // namespace content