Pass preallocation hints to SkRWBuffer

third_party/WebKit/Source/platform/graphics/DeferredImageDecoder.cpp

 /*
  * Copyright (C) 2012 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 147 matching lines @@
     prepareLazyDecodedFrames();
   }
 
   if (m_frameGenerator) {
     if (!m_rwBuffer)
       m_rwBuffer = wrapUnique(new SkRWBuffer(data->size()));
 
     const char* segment = 0;
     for (size_t length = data->getSomeData(segment, m_rwBuffer->size()); length;
          length = data->getSomeData(segment, m_rwBuffer->size())) {
-      m_rwBuffer->append(segment, length);
+      DCHECK_GE(data->size(), m_rwBuffer->size() + length);
+      const size_t remaining = data->size() - m_rwBuffer->size() - length;
+      m_rwBuffer->append(segment, length, remaining);
     }
   }
 }
 
 bool DeferredImageDecoder::isSizeAvailable() {
   // m_actualDecoder is 0 only if image decoding is deferred and that means
   // the image header decoded successfully and the size is available.
   return m_actualDecoder ? m_actualDecoder->isSizeAvailable() : true;
 }
 
@@ skipping 182 matching lines @@
 
 namespace WTF {
 template <>
 struct VectorTraits<blink::DeferredFrameData>
     : public SimpleClassVectorTraits<blink::DeferredFrameData> {
   STATIC_ONLY(VectorTraits);
   static const bool canInitializeWithMemset =
       false;  // Not all DeferredFrameData members initialize to 0.
 };
 }