Purge image frame after checking for sufficient data.

third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoder.cpp

 /*
  * Copyright (C) 2006 Apple Computer, 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.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 317 matching lines @@
   } while (frameToDecode != kNotFound &&
            m_frameBufferCache[frameToDecode].getStatus() !=
                ImageFrame::FrameComplete);
 
   for (auto i = framesToDecode.rbegin(); i != framesToDecode.rend(); ++i) {
     if (!m_reader->decode(*i)) {
       setFailed();
       return;
     }
 
-    if (m_purgeAggressively)
-      clearCacheExceptFrame(*i);
-
     // We need more data to continue decoding.
     if (m_frameBufferCache[*i].getStatus() != ImageFrame::FrameComplete)
       break;
+
+    if (m_purgeAggressively)
+      clearCacheExceptFrame(*i);
   }
 
   // It is also a fatal error if all data is received and we have decoded all
   // frames available but the file is truncated.
   if (index >= m_frameBufferCache.size() - 1 && isAllDataReceived() &&
       m_reader && !m_reader->parseCompleted())
     setFailed();
 }
 
 void GIFImageDecoder::parse(GIFParseQuery query) {
@@ skipping 86 matching lines @@
     m_purgeAggressively = true;
     return;
   }
 
   const uint64_t totalMemoryUsage = frameMemoryUsage * index;
   if (totalMemoryUsage > m_maxDecodedBytes) {
     m_purgeAggressively = true;
   }
 }
 }  // namespace blink