blink: Allow image decodes to work without a Platform

Source/platform/image-decoders/ImageDecoder.cpp

Index: Source/platform/image-decoders/ImageDecoder.cpp
diff --git a/Source/platform/image-decoders/ImageDecoder.cpp b/Source/platform/image-decoders/ImageDecoder.cpp
index 0982e7fa7ca83972844551151d6dc11a982a2158..9c7c2b9177503ef5f756763499ed913d77c4e759 100644
--- a/Source/platform/image-decoders/ImageDecoder.cpp
+++ b/Source/platform/image-decoders/ImageDecoder.cpp
@@ -88,7 +88,7 @@ PassOwnPtr<ImageDecoder> ImageDecoder::create(const SharedBuffer& data, ImageSou
     const unsigned longestSignatureLength = sizeof("RIFF????WEBPVP") - 1;
     ASSERT(longestSignatureLength == 14);
 
-    size_t maxDecodedBytes = Platform::current()->maxDecodedImageBytes();
+    size_t maxDecodedBytes = Platform::current() ? Platform::current()->maxDecodedImageBytes() : noDecodedImageByteLimit;
 
     char contents[longestSignatureLength];
     if (copyFromSharedBuffer(contents, longestSignatureLength, data, 0) < longestSignatureLength)