WebP animation: Loop once more than stored loop count.

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 209 matching lines @@
         m_formatFlags = WebPDemuxGetI(m_demux, WEBP_FF_FORMAT_FLAGS);
         if (!(m_formatFlags & ANIMATION_FLAG)) {
             m_repetitionCount = cAnimationNone;
         } else {
             // Since we have parsed at least one frame, even if partially,
             // the global animation (ANIM) properties have been read since
             // an ANIM chunk must precede the ANMF frame chunks.
             m_repetitionCount = WebPDemuxGetI(m_demux, WEBP_FF_LOOP_COUNT);
             // Repetition count is always <= 16 bits.
             ASSERT(m_repetitionCount == (m_repetitionCount & 0xffff));
-            // Repetition count is the number of animation cycles to show,
-            // where 0 means "infinite". But ImageSource::repetitionCount()
-            // returns -1 for "infinite", and 0 and up for "show the image
-            // animation one cycle more than the value". Subtract one here
-            // to correctly handle the finite and infinite cases.
-            --m_repetitionCount;
+            if (!m_repetitionCount)
+                m_repetitionCount = cAnimationLoopInfinite;
             // FIXME: Implement ICC profile support for animated images.
             m_formatFlags &= ~ICCP_FLAG;
         }
 
 #if USE(QCMSLIB)
         if ((m_formatFlags & ICCP_FLAG) && !ignoresGammaAndColorProfile())
             readColorProfile();
 #endif
     }
 
@@ skipping 310 matching lines @@
             return false;
         }
         // FALLTHROUGH
     default:
         clear();
         return setFailed();
     }
 }
 
 } // namespace blink