Fix errors caused by unsafe conversions to/from size_t

third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp

Index: third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp
diff --git a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp
index b660c660eb881bd73c788b7b7b1f43c765f20169..b1cac4d49cf6f40825fc7d431b401caa3a8a4955 100644
--- a/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp
+++ b/third_party/WebKit/Source/platform/image-decoders/ImageDecoder.cpp
@@ -32,12 +32,12 @@
 
 namespace blink {
 
-static unsigned copyFromSharedBuffer(char* buffer, unsigned bufferLength, const SharedBuffer& sharedBuffer, unsigned offset)
+static size_t copyFromSharedBuffer(char* buffer, size_t bufferLength, const SharedBuffer& sharedBuffer, size_t offset)
 {
-    unsigned bytesExtracted = 0;
+    size_t bytesExtracted = 0;
     const char* moreData;
-    while (unsigned moreDataLength = sharedBuffer.getSomeData(moreData, offset)) {
-        unsigned bytesToCopy = std::min(bufferLength - bytesExtracted, moreDataLength);
+    while (size_t moreDataLength = sharedBuffer.getSomeData(moreData, offset)) {
+        size_t bytesToCopy = std::min(bufferLength - bytesExtracted, moreDataLength);
         memcpy(buffer + bytesExtracted, moreData, bytesToCopy);
         bytesExtracted += bytesToCopy;
         if (bytesExtracted == bufferLength)
@@ -84,7 +84,7 @@ inline bool matchesBMPSignature(char* contents)
 
 PassOwnPtr<ImageDecoder> ImageDecoder::create(const SharedBuffer& data, AlphaOption alphaOption, GammaAndColorProfileOption colorOptions)
 {
-    const unsigned longestSignatureLength = sizeof("RIFF????WEBPVP") - 1;
+    const size_t longestSignatureLength = sizeof("RIFF????WEBPVP") - 1;
     ASSERT(longestSignatureLength == 14);
 
     size_t maxDecodedBytes = Platform::current() ? Platform::current()->maxDecodedImageBytes() : noDecodedImageByteLimit;