Pass SkPaint instead of its alpha and mode in WebMediaPlayer::paint

content/renderer/media/html_video_element_capturer_source.cc

 // 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 "content/renderer/media/html_video_element_capturer_source.h"
 
 #include "base/location.h"
 #include "base/memory/ptr_util.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
@@ skipping 117 matching lines @@
   TRACE_EVENT0("video", "HtmlVideoElementCapturerSource::sendNewFrame");
   DCHECK(thread_checker_.CalledOnValidThread());
 
   if (!web_media_player_ || new_frame_callback_.is_null())
     return;
 
   const base::TimeTicks current_time = base::TimeTicks::Now();
   const blink::WebSize resolution = web_media_player_->naturalSize();
 
   SkCanvas* canvas = surface_->getCanvas();
+  SkPaint paint;
+  paint.setXfermodeMode(SkXfermode::kSrc_Mode);
+  paint.setFilterQuality(kLow_SkFilterQuality);

[chcunningham, 2016/09/06 23:07:33]

Are you missing a call to setAlpha(0xFF)? Does this line replace that call?

[xidachen, 2016/09/07 13:23:07]

The 0xFF is by default when the SkPaint is defined. As you can see in this line:
https://cs.chromium.org/chromium/src/third_party/skia/src/core/SkPaint.cpp?sq...

   web_media_player_->paint(
       canvas, blink::WebRect(0, 0, resolution.width, resolution.height),
-      0xFF /* alpha */, SkXfermode::kSrc_Mode);
+      paint);
   DCHECK_NE(kUnknown_SkColorType, canvas->imageInfo().colorType());
   DCHECK_EQ(canvas->imageInfo().width(), resolution.width);
   DCHECK_EQ(canvas->imageInfo().height(), resolution.height);
 
   const SkBitmap bitmap = skia::ReadPixels(canvas);
   DCHECK_NE(kUnknown_SkColorType, bitmap.colorType());
   DCHECK(!bitmap.drawsNothing());
   DCHECK(bitmap.getPixels());
   if (bitmap.colorType() != kN32_SkColorType) {
     DLOG(ERROR) << "Only supported color type is kN32_SkColorType (ARGB/ABGR)";
@@ skipping 43 matching lines @@
       next_capture_time_ = current_time;
   }
   // Schedule next capture.
   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
       FROM_HERE, base::Bind(&HtmlVideoElementCapturerSource::sendNewFrame,
                             weak_factory_.GetWeakPtr()),
       next_capture_time_ - current_time);
 }
 
 }  // namespace content