Fix errors caused by unsafe conversions to/from size_t

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

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "platform/image-decoders/ImageDecoderTestHelpers.h"
 
 #include "platform/SharedBuffer.h"
 #include "platform/image-decoders/ImageDecoder.h"
 #include "platform/image-decoders/ImageFrame.h"
 #include "platform/testing/UnitTestHelpers.h"
@@ skipping 57 matching lines @@
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     size_t frameCount = 0;
     size_t framesDecoded = 0;
 
     // Pass data to decoder byte by byte.
     RefPtr<SharedBuffer> sourceData[2] = { SharedBuffer::create(), SharedBuffer::create() };
     const char* source = data->data();
 
     for (size_t length = 1; length <= data->size() && !decoder->failed(); ++length) {
-        sourceData[0]->append(source, 1);
-        sourceData[1]->append(source++, 1);
+        sourceData[0]->append(source, 1u);
+        sourceData[1]->append(source++, 1u);
         // Alternate the buffers to cover the JPEGImageDecoder::onSetData restart code.
         decoder->setData(sourceData[length & 1].get(), length == data->size());
 
         EXPECT_LE(frameCount, decoder->frameCount());
         frameCount = decoder->frameCount();
 
         if (!decoder->isSizeAvailable())
             continue;
 
         ImageFrame* frame = decoder->frameBufferAtIndex(frameCount - 1);
@@ skipping 42 matching lines @@
     // data in a segment, its pointer would no longer be valid.
     segmentedData->data();
 
     ImageFrame* frame = decoder->frameBufferAtIndex(0);
     ASSERT_FALSE(decoder->failed());
     EXPECT_EQ(frame->status(), ImageFrame::FrameComplete);
     EXPECT_EQ(hashBitmap(frame->bitmap()), hash);
 }
 
 } // namespace blink