Cap memory usage in webp catch up

third_party/WebKit/Source/platform/image-decoders/webp/WEBPImageDecoder.cpp

 /*
  * Copyright (C) 2010 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.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 238 matching lines @@
         m_repetitionCount = cAnimationLoopInfinite;
       // FIXME: Implement ICC profile support for animated images.
       m_formatFlags &= ~ICCP_FLAG;
     }
 
     if ((m_formatFlags & ICCP_FLAG) && !ignoresGammaAndColorProfile())
       readColorProfile();
   }
 
   ASSERT(isDecodedSizeAvailable());
+
+  size_t frameCount = WebPDemuxGetI(m_demux, WEBP_FF_FRAME_COUNT);
+  updateAggressivePurging(frameCount);
+
   return true;
 }
 
 bool WEBPImageDecoder::initFrameBuffer(size_t frameIndex) {
   ImageFrame& buffer = m_frameBufferCache[frameIndex];
   if (buffer.getStatus() != ImageFrame::FrameEmpty)  // Already initialized.
     return true;
 
   const size_t requiredPreviousFrameIndex = buffer.requiredPreviousFrameIndex();
   if (requiredPreviousFrameIndex == kNotFound) {
@@ skipping 210 matching lines @@
     } else {
       decodeSingleFrame(webpFrame.fragment.bytes, webpFrame.fragment.size, *i);
       WebPDemuxReleaseIterator(&webpFrame);
     }
     if (failed())
       return;
 
     // 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_demux && m_demuxState != WEBP_DEMUX_DONE)
     setFailed();
 }
 
 bool WEBPImageDecoder::decodeSingleFrame(const uint8_t* dataBytes,
@@ skipping 58 matching lines @@
         return false;
       }
     // FALLTHROUGH
     default:
       clear();
       return setFailed();
   }
 }
 
 }  // namespace blink