Propagate the decoder frame premul info to SkBitmap

third_party/WebKit/Source/platform/image-decoders/ImageFrame.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2008, 2009 Google, Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 80 matching lines @@
     m_hasAlpha = other.m_hasAlpha;
     m_bitmap.reset();
     return other.m_bitmap.copyTo(&m_bitmap, other.m_bitmap.colorType());
 }
 
 bool ImageFrame::setSize(int newWidth, int newHeight)
 {
     // setSize() should only be called once, it leaks memory otherwise.
     ASSERT(!width() && !height());
 
-    m_bitmap.setInfo(SkImageInfo::MakeN32Premul(newWidth, newHeight));
+    m_bitmap.setInfo(SkImageInfo::MakeN32(newWidth, newHeight, computeAlphaType()));
     if (!m_bitmap.tryAllocPixels(m_allocator, 0))

[Noel Gordon, 2016/03/21 22:37:16]

Maybe don't call computeAlphaType() here?  Instead use m_premultiplyAlpha ?
kPremul_SkAlphaType : kUnpremul_SkAlphaType;

[f(malita), 2016/03/21 22:46:24]

Done.

         return false;
 
     zeroFillPixelData();
     return true;
 }
 
 const SkBitmap& ImageFrame::bitmap() const
 {
     return m_bitmap;
 }
 
 bool ImageFrame::hasAlpha() const
 {
     return m_hasAlpha;
 }
 
 void ImageFrame::setHasAlpha(bool alpha)
 {
     m_hasAlpha = alpha;
 
-    // If the frame is not fully loaded, there will be transparent pixels,
-    // so we can't tell skia we're opaque, even for image types that logically
-    // always are (e.g. jpeg).
-    if (m_status != FrameComplete)
-        alpha = true;
-    m_bitmap.setAlphaType(alpha ? kPremul_SkAlphaType : kOpaque_SkAlphaType);
+    m_bitmap.setAlphaType(computeAlphaType());
 }
 
 void ImageFrame::setStatus(Status status)
 {
     m_status = status;
     if (m_status == FrameComplete) {
-        m_bitmap.setAlphaType(m_hasAlpha ? kPremul_SkAlphaType : kOpaque_SkAlphaType);
+        m_bitmap.setAlphaType(computeAlphaType());
         // Send pending pixels changed notifications now, because we can't do this after
         // the bitmap has been marked immutable.
         notifyBitmapIfPixelsChanged();
         m_bitmap.setImmutable(); // Tell the bitmap it's done.
     }
 }
 
 void ImageFrame::zeroFillFrameRect(const IntRect& rect)
 {
     if (rect.isEmpty())
         return;
 
     m_bitmap.eraseArea(rect, SkColorSetARGB(0, 0, 0, 0));
     setHasAlpha(true);
 }
 
+SkAlphaType ImageFrame::computeAlphaType() const
+{
+    // If the frame is not fully loaded, there will be transparent pixels,
+    // so we can't tell skia we're opaque, even for image types that logically
+    // always are (e.g. jpeg).
+    if (!m_hasAlpha && m_status == FrameComplete)
+        return kOpaque_SkAlphaType;
+
+    return m_premultiplyAlpha ? kPremul_SkAlphaType : kUnpremul_SkAlphaType;
+}
+
 } // namespace blink