Refactor ImageDecoder factories

third_party/WebKit/Source/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.
  *
  * 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.
@@ skipping 33 matching lines @@
 size_t ImageSource::clearCacheExceptFrame(size_t clearExceptFrame)
 {
     return m_decoder ? m_decoder->clearCacheExceptFrame(clearExceptFrame) : 0;
 }
 
 PassRefPtr<SharedBuffer> ImageSource::data()
 {
     return m_decoder ? m_decoder->data() : nullptr;
 }
 
-ImageDecoder::SniffResult ImageSource::setData(SharedBuffer& data, bool allDataReceived)
+bool ImageSource::setData(PassRefPtr<SharedBuffer> passData, bool allDataReceived)
 {
-    ImageDecoder::SniffResult result = ImageDecoder::determineImageType(data);
-    if (!m_decoder)
-        m_decoder = DeferredImageDecoder::create(result, ImageDecoder::AlphaPremultiplied, ImageDecoder::GammaAndColorProfileApplied);
+    RefPtr<SharedBuffer> data = passData;
 
-    if (m_decoder)
-        m_decoder->setData(data, allDataReceived);
+    if (m_decoder) {
+        m_decoder->setData(data.release(), allDataReceived);
+        // If the decoder is pre-instantiated, it means we've already validated the data/signature
+        // at some point.
+        return true;
+    }
 
-    return result;
+    m_decoder = DeferredImageDecoder::create(data, allDataReceived, ImageDecoder::AlphaPremultiplied, ImageDecoder::GammaAndColorProfileApplied);
+
+    // Insufficient data is not a failure.
+    return m_decoder || !ImageDecoder::hasSufficientDataToSniffImageType(*data);
 }
 
 String ImageSource::filenameExtension() const
 {
     return m_decoder ? m_decoder->filenameExtension() : String();
 }
 
 bool ImageSource::isSizeAvailable()
 {
     return m_decoder && m_decoder->isSizeAvailable();
@@ skipping 73 matching lines @@
 {
     return m_decoder && m_decoder->frameIsCompleteAtIndex(index);
 }
 
 size_t ImageSource::frameBytesAtIndex(size_t index) const
 {
     return m_decoder ? m_decoder->frameBytesAtIndex(index) : 0;
 }
 
 } // namespace blink