Checking if frame is complete and access duration doesn't need a decode

Source/core/platform/graphics/ImageSource.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp.toker@collabora.co.uk>
  * Copyright (C) 2008, Google Inc. All rights reserved.
  * Copyright (C) 2007-2009 Torch Mobile, 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
@@ skipping 138 matching lines @@
     // Zero-height images can cause problems for some ports.  If we have an
     // empty image dimension, just bail.
     if (size().isEmpty())
         return 0;
 
     // Return the buffer contents as a native image.  For some ports, the data
     // is already in a native container, and this just increments its refcount.
     return buffer->asNewNativeImage();
 }
 
-float ImageSource::frameDurationAtIndex(size_t index)
+float ImageSource::frameDurationAtIndex(size_t index) const
 {
     if (!m_decoder)
         return 0;
 
-    ImageFrame* buffer = m_decoder->frameBufferAtIndex(index);
-    if (!buffer || buffer->status() == ImageFrame::FrameEmpty)
-        return 0;
-
     // Many annoying ads specify a 0 duration to make an image flash as quickly as possible.
     // We follow Firefox's behavior and use a duration of 100 ms for any frames that specify
     // a duration of <= 10 ms. See <rdar://problem/7689300> and <http://webkit.org/b/36082>
     // for more information.
-    const float duration = buffer->duration() / 1000.0f;
+    const float duration = m_decoder->frameDurationAtIndex(index) / 1000.0f;
     if (duration < 0.011f)
         return 0.100f;
     return duration;
 }
 
 ImageOrientation ImageSource::orientationAtIndex(size_t) const
 {
     return m_decoder ? m_decoder->orientation() : DefaultImageOrientation;
 }
 
-bool ImageSource::frameHasAlphaAtIndex(size_t index)
+bool ImageSource::frameHasAlphaAtIndex(size_t index) const
 {
-    if (!m_decoder)
-        return true;
-    return m_decoder->frameHasAlphaAtIndex(index);
+    return !m_decoder || m_decoder->frameHasAlphaAtIndex(index);
 }
 
-bool ImageSource::frameIsCompleteAtIndex(size_t index)
+bool ImageSource::frameIsCompleteAtIndex(size_t index) const
 {
-    if (!m_decoder)
-        return false;
-
-    ImageFrame* buffer = m_decoder->frameBufferAtIndex(index);
-    return buffer && buffer->status() == ImageFrame::FrameComplete;
+    return m_decoder && m_decoder->frameIsCompleteAtIndex(index);
 }
 
 unsigned ImageSource::frameBytesAtIndex(size_t index) const
 {
     if (!m_decoder)
         return 0;
     return m_decoder->frameBytesAtIndex(index);
 }
 
 void ImageSource::reportMemoryUsage(MemoryObjectInfo* memoryObjectInfo) const
 {
     MemoryClassInfo info(memoryObjectInfo, this, PlatformMemoryTypes::Image);
     info.addMember(m_decoder, "decoder");
 }
 
 }