Don't show a placeholder if the response contains the full image.

third_party/WebKit/Source/platform/network/HTTPParsers.cpp

 /*
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. http://www.torchmobile.com/
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple 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:
@@ skipping 892 matching lines @@
                                            int maxParseDepth) {
   StringBuilder sb;
   sb.append("[");
   sb.append(header);
   sb.append("]");
   std::unique_ptr<JSONValue> headerValue =
       parseJSON(sb.toString(), maxParseDepth);
   return JSONArray::from(std::move(headerValue));
 }
 
+bool parseContentRangeHeader(const String& contentRange,
+                             int64_t* firstBytePosition,
+                             int64_t* lastBytePosition,
+                             int64_t* instanceLength) {
+  return net::HttpUtil::ParseContentRangeHeader(
+      StringUTF8Adaptor(contentRange).asStringPiece(), firstBytePosition,
+      lastBytePosition, instanceLength);
+}
+
 }  // namespace blink