Eliminate copies of encoded image data

third_party/WebKit/Source/platform/image-decoders/gif/GIFImageDecoderTest.cpp

 /*
  * Copyright (C) 2013 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 14 matching lines @@
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "platform/image-decoders/gif/GIFImageDecoder.h"
 
 #include "platform/SharedBuffer.h"
 #include "platform/image-decoders/ImageDecoderTestHelpers.h"
+#include "platform/image-decoders/SharedBufferSegmentReader.h"
 #include "public/platform/WebData.h"
 #include "public/platform/WebSize.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "wtf/OwnPtr.h"
 #include "wtf/PassOwnPtr.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
 namespace {
@@ skipping 12 matching lines @@
     SCOPED_TRACE(gifFile);
 
     RefPtr<SharedBuffer> fullData = readFile(dir, gifFile);
     ASSERT_TRUE(fullData.get());
     Vector<unsigned> baselineHashes;
     createDecodingBaseline(&createDecoder, fullData.get(), &baselineHashes);
     size_t frameCount = baselineHashes.size();
 
     // Random decoding should get the same results as sequential decoding.
     OwnPtr<ImageDecoder> decoder = createDecoder();
-    decoder->setData(fullData.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(fullData));
+    decoder->setData(segmentReader.get(), true);
     const size_t skippingStep = 5;
     for (size_t i = 0; i < skippingStep; ++i) {
         for (size_t j = i; j < frameCount; j += skippingStep) {
             SCOPED_TRACE(testing::Message() << "Random i:" << i << " j:" << j);
             ImageFrame* frame = decoder->frameBufferAtIndex(j);
             EXPECT_EQ(baselineHashes[j], hashBitmap(frame->getSkBitmap()));
         }
     }
 
     // Decoding in reverse order.
     decoder = createDecoder();
-    decoder->setData(fullData.get(), true);
+    decoder->setData(segmentReader.get(), true);
     for (size_t i = frameCount; i; --i) {
         SCOPED_TRACE(testing::Message() << "Reverse i:" << i);
         ImageFrame* frame = decoder->frameBufferAtIndex(i - 1);
         EXPECT_EQ(baselineHashes[i - 1], hashBitmap(frame->getSkBitmap()));
     }
 }
 
 void testRandomDecodeAfterClearFrameBufferCache(const char* dir, const char* gifFile)
 {
     SCOPED_TRACE(gifFile);
 
     RefPtr<SharedBuffer> data = readFile(dir, gifFile);
     ASSERT_TRUE(data.get());
     Vector<unsigned> baselineHashes;
     createDecodingBaseline(&createDecoder, data.get(), &baselineHashes);
     size_t frameCount = baselineHashes.size();
 
     OwnPtr<ImageDecoder> decoder = createDecoder();
-    decoder->setData(data.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+    decoder->setData(segmentReader.get(), true);
     for (size_t clearExceptFrame = 0; clearExceptFrame < frameCount; ++clearExceptFrame) {
         decoder->clearCacheExceptFrame(clearExceptFrame);
         const size_t skippingStep = 5;
         for (size_t i = 0; i < skippingStep; ++i) {
             for (size_t j = 0; j < frameCount; j += skippingStep) {
                 SCOPED_TRACE(testing::Message() << "Random i:" << i << " j:" << j);
                 ImageFrame* frame = decoder->frameBufferAtIndex(j);
                 EXPECT_EQ(baselineHashes[j], hashBitmap(frame->getSkBitmap()));
             }
         }
     }
 }
 
 } // anonymous namespace
 
 TEST(GIFImageDecoderTest, decodeTwoFrames)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     RefPtr<SharedBuffer> data = readFile(layoutTestResourcesDir, "animated.gif");
     ASSERT_TRUE(data.get());
-    decoder->setData(data.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+    decoder->setData(segmentReader.get(), true);
     EXPECT_EQ(cAnimationLoopOnce, decoder->repetitionCount());
 
     ImageFrame* frame = decoder->frameBufferAtIndex(0);
     uint32_t generationID0 = frame->getSkBitmap().getGenerationID();
     EXPECT_EQ(ImageFrame::FrameComplete, frame->status());
     EXPECT_EQ(16, frame->getSkBitmap().width());
     EXPECT_EQ(16, frame->getSkBitmap().height());
 
     frame = decoder->frameBufferAtIndex(1);
     uint32_t generationID1 = frame->getSkBitmap().getGenerationID();
     EXPECT_EQ(ImageFrame::FrameComplete, frame->status());
     EXPECT_EQ(16, frame->getSkBitmap().width());
     EXPECT_EQ(16, frame->getSkBitmap().height());
     EXPECT_TRUE(generationID0 != generationID1);
 
     EXPECT_EQ(2u, decoder->frameCount());
     EXPECT_EQ(cAnimationLoopInfinite, decoder->repetitionCount());
 }
 
 TEST(GIFImageDecoderTest, parseAndDecode)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     RefPtr<SharedBuffer> data = readFile(layoutTestResourcesDir, "animated.gif");
     ASSERT_TRUE(data.get());
-    decoder->setData(data.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+    decoder->setData(segmentReader.get(), true);
     EXPECT_EQ(cAnimationLoopOnce, decoder->repetitionCount());
 
     // This call will parse the entire file.
     EXPECT_EQ(2u, decoder->frameCount());
 
     ImageFrame* frame = decoder->frameBufferAtIndex(0);
     EXPECT_EQ(ImageFrame::FrameComplete, frame->status());
     EXPECT_EQ(16, frame->getSkBitmap().width());
     EXPECT_EQ(16, frame->getSkBitmap().height());
 
     frame = decoder->frameBufferAtIndex(1);
     EXPECT_EQ(ImageFrame::FrameComplete, frame->status());
     EXPECT_EQ(16, frame->getSkBitmap().width());
     EXPECT_EQ(16, frame->getSkBitmap().height());
     EXPECT_EQ(cAnimationLoopInfinite, decoder->repetitionCount());
 }
 
+// FIXME: Call ImageDecoderTestHelpers' testByteByByteDecode
 TEST(GIFImageDecoderTest, parseByteByByte)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     RefPtr<SharedBuffer> data = readFile(layoutTestResourcesDir, "animated.gif");
     ASSERT_TRUE(data.get());
 
     size_t frameCount = 0;
 
     // Pass data to decoder byte by byte.
     for (size_t length = 1; length <= data->size(); ++length) {
         RefPtr<SharedBuffer> tempData = SharedBuffer::create(data->data(), length);
-        decoder->setData(tempData.get(), length == data->size());
+        RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(tempData));
+        decoder->setData(segmentReader.get(), length == data->size());
 
         EXPECT_LE(frameCount, decoder->frameCount());
         frameCount = decoder->frameCount();
     }
 
     EXPECT_EQ(2u, decoder->frameCount());
 
     decoder->frameBufferAtIndex(0);
     decoder->frameBufferAtIndex(1);
     EXPECT_EQ(cAnimationLoopInfinite, decoder->repetitionCount());
 }
 
 TEST(GIFImageDecoderTest, parseAndDecodeByteByByte)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     RefPtr<SharedBuffer> data = readFile(layoutTestResourcesDir, "animated-gif-with-offsets.gif");
     ASSERT_TRUE(data.get());
 
     size_t frameCount = 0;
     size_t framesDecoded = 0;
 
     // Pass data to decoder byte by byte.
     for (size_t length = 1; length <= data->size(); ++length) {
         RefPtr<SharedBuffer> tempData = SharedBuffer::create(data->data(), length);
-        decoder->setData(tempData.get(), length == data->size());
+        RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+        decoder->setData(segmentReader.get(), length == data->size());
 
         EXPECT_LE(frameCount, decoder->frameCount());
         frameCount = decoder->frameCount();
 
         ImageFrame* frame = decoder->frameBufferAtIndex(frameCount - 1);
         if (frame && frame->status() == ImageFrame::FrameComplete && framesDecoded < frameCount)
             ++framesDecoded;
     }
 
     EXPECT_EQ(5u, decoder->frameCount());
     EXPECT_EQ(5u, framesDecoded);
     EXPECT_EQ(cAnimationLoopInfinite, decoder->repetitionCount());
 }
 
 TEST(GIFImageDecoderTest, brokenSecondFrame)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     RefPtr<SharedBuffer> data = readFile(webTestsDataDir, "broken.gif");
     ASSERT_TRUE(data.get());
-    decoder->setData(data.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+    decoder->setData(segmentReader.get(), true);
 
     // One frame is detected but cannot be decoded.
     EXPECT_EQ(1u, decoder->frameCount());
     ImageFrame* frame = decoder->frameBufferAtIndex(1);
     EXPECT_FALSE(frame);
 }
 
 TEST(GIFImageDecoderTest, progressiveDecode)
 {
     RefPtr<SharedBuffer> fullData = readFile(webTestsDataDir, "radient.gif");
     ASSERT_TRUE(fullData.get());
     const size_t fullLength = fullData->size();
 
     OwnPtr<ImageDecoder> decoder;
     ImageFrame* frame;
 
     Vector<unsigned> truncatedHashes;
     Vector<unsigned> progressiveHashes;
 
     // Compute hashes when the file is truncated.
     const size_t increment = 1;
     for (size_t i = 1; i <= fullLength; i += increment) {
         decoder = createDecoder();
         RefPtr<SharedBuffer> data = SharedBuffer::create(fullData->data(), i);
-        decoder->setData(data.get(), i == fullLength);
+        RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+        decoder->setData(segmentReader.get(), i == fullLength);
         frame = decoder->frameBufferAtIndex(0);
         if (!frame) {
             truncatedHashes.append(0);
             continue;
         }
         truncatedHashes.append(hashBitmap(frame->getSkBitmap()));
     }
 
     // Compute hashes when the file is progressively decoded.
     decoder = createDecoder();
     EXPECT_EQ(cAnimationLoopOnce, decoder->repetitionCount());
     for (size_t i = 1; i <= fullLength; i += increment) {
         RefPtr<SharedBuffer> data = SharedBuffer::create(fullData->data(), i);
-        decoder->setData(data.get(), i == fullLength);
+        RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+        decoder->setData(segmentReader.get(), i == fullLength);
         frame = decoder->frameBufferAtIndex(0);
         if (!frame) {
             progressiveHashes.append(0);
             continue;
         }
         progressiveHashes.append(hashBitmap(frame->getSkBitmap()));
     }
     EXPECT_EQ(cAnimationNone, decoder->repetitionCount());
 
     bool match = true;
     for (size_t i = 0; i < truncatedHashes.size(); ++i) {
         if (truncatedHashes[i] != progressiveHashes[i]) {
             match = false;
             break;
         }
     }
     EXPECT_TRUE(match);
 }
 
 TEST(GIFImageDecoderTest, allDataReceivedTruncation)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     RefPtr<SharedBuffer> data = readFile(layoutTestResourcesDir, "animated.gif");
     ASSERT_TRUE(data.get());
 
     ASSERT_GE(data->size(), 10u);
     RefPtr<SharedBuffer> tempData = SharedBuffer::create(data->data(), data->size() - 10);
-    decoder->setData(tempData.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(tempData));
+    decoder->setData(segmentReader.get(), true);
 
     EXPECT_EQ(2u, decoder->frameCount());
     EXPECT_FALSE(decoder->failed());
 
     decoder->frameBufferAtIndex(0);
     EXPECT_FALSE(decoder->failed());
     decoder->frameBufferAtIndex(1);
     EXPECT_TRUE(decoder->failed());
 }
 
 TEST(GIFImageDecoderTest, frameIsComplete)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     RefPtr<SharedBuffer> data = readFile(layoutTestResourcesDir, "animated.gif");
     ASSERT_TRUE(data.get());
-    decoder->setData(data.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+    decoder->setData(segmentReader.get(), true);
 
     EXPECT_EQ(2u, decoder->frameCount());
     EXPECT_FALSE(decoder->failed());
     EXPECT_TRUE(decoder->frameIsCompleteAtIndex(0));
     EXPECT_TRUE(decoder->frameIsCompleteAtIndex(1));
     EXPECT_EQ(cAnimationLoopInfinite, decoder->repetitionCount());
 }
 
 TEST(GIFImageDecoderTest, frameIsCompleteLoading)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     RefPtr<SharedBuffer> data = readFile(layoutTestResourcesDir, "animated.gif");
     ASSERT_TRUE(data.get());
 
     ASSERT_GE(data->size(), 10u);
     RefPtr<SharedBuffer> tempData = SharedBuffer::create(data->data(), data->size() - 10);
-    decoder->setData(tempData.get(), false);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(tempData));
+    decoder->setData(segmentReader.get(), false);
 
     EXPECT_EQ(2u, decoder->frameCount());
     EXPECT_FALSE(decoder->failed());
     EXPECT_TRUE(decoder->frameIsCompleteAtIndex(0));
     EXPECT_FALSE(decoder->frameIsCompleteAtIndex(1));
 
-    decoder->setData(data.get(), true);
+    segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+    decoder->setData(segmentReader.get(), true);
     EXPECT_EQ(2u, decoder->frameCount());
     EXPECT_TRUE(decoder->frameIsCompleteAtIndex(0));
     EXPECT_TRUE(decoder->frameIsCompleteAtIndex(1));
 }
 
 TEST(GIFImageDecoderTest, badTerminator)
 {
     RefPtr<SharedBuffer> referenceData = readFile(webTestsDataDir, "radient.gif");
     RefPtr<SharedBuffer> testData = readFile(webTestsDataDir, "radient-bad-terminator.gif");
     ASSERT_TRUE(referenceData.get());
     ASSERT_TRUE(testData.get());
 
     OwnPtr<ImageDecoder> referenceDecoder = createDecoder();
-    referenceDecoder->setData(referenceData.get(), true);
+    RefPtr<SharedBufferSegmentReader> referenceSharedBufferSegmentReader = adoptRef(new SharedBufferSegmentReader(referenceData));
+    referenceDecoder->setData(referenceSharedBufferSegmentReader.get(), true);
     EXPECT_EQ(1u, referenceDecoder->frameCount());
     ImageFrame* referenceFrame = referenceDecoder->frameBufferAtIndex(0);
     ASSERT(referenceFrame);
 
     OwnPtr<ImageDecoder> testDecoder = createDecoder();
-    testDecoder->setData(testData.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(testData));
+    testDecoder->setData(segmentReader.get(), true);
     EXPECT_EQ(1u, testDecoder->frameCount());
     ImageFrame* testFrame = testDecoder->frameBufferAtIndex(0);
     ASSERT(testFrame);
 
     EXPECT_EQ(hashBitmap(referenceFrame->getSkBitmap()), hashBitmap(testFrame->getSkBitmap()));
 }
 
 TEST(GIFImageDecoderTest, updateRequiredPreviousFrameAfterFirstDecode)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     RefPtr<SharedBuffer> fullData = readFile(layoutTestResourcesDir, "animated-10color.gif");
     ASSERT_TRUE(fullData.get());
 
     // Give it data that is enough to parse but not decode in order to check the status
     // of requiredPreviousFrameIndex before decoding.
     size_t partialSize = 1;
     do {
         RefPtr<SharedBuffer> data = SharedBuffer::create(fullData->data(), partialSize);
-        decoder->setData(data.get(), false);
+        RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+        decoder->setData(segmentReader.get(), false);
         ++partialSize;
     } while (!decoder->frameCount() || decoder->frameBufferAtIndex(0)->status() == ImageFrame::FrameEmpty);
 
     EXPECT_EQ(kNotFound, decoder->frameBufferAtIndex(0)->requiredPreviousFrameIndex());
     unsigned frameCount = decoder->frameCount();
     for (size_t i = 1; i < frameCount; ++i)
         EXPECT_EQ(i - 1, decoder->frameBufferAtIndex(i)->requiredPreviousFrameIndex());
 
-    decoder->setData(fullData.get(), true);
+    RefPtr<SegmentReader> fullSegmentReader = adoptRef(new SharedBufferSegmentReader(fullData));
+    decoder->setData(fullSegmentReader.get(), true);
     for (size_t i = 0; i < frameCount; ++i)
         EXPECT_EQ(kNotFound, decoder->frameBufferAtIndex(i)->requiredPreviousFrameIndex());
 }
 
 TEST(GIFImageDecoderTest, randomFrameDecode)
 {
     // Single frame image.
     testRandomFrameDecode(webTestsDataDir, "radient.gif");
     // Multiple frame images.
     testRandomFrameDecode(layoutTestResourcesDir, "animated-gif-with-offsets.gif");
@@ skipping 16 matching lines @@
     Vector<unsigned> baselineHashes;
     createDecodingBaseline(&createDecoder, fullData.get(), &baselineHashes);
     size_t frameCount = baselineHashes.size();
 
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     // Let frame 0 be partially decoded.
     size_t partialSize = 1;
     do {
         RefPtr<SharedBuffer> data = SharedBuffer::create(fullData->data(), partialSize);
-        decoder->setData(data.get(), false);
+        RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+        decoder->setData(segmentReader.get(), false);
         ++partialSize;
     } while (!decoder->frameCount() || decoder->frameBufferAtIndex(0)->status() == ImageFrame::FrameEmpty);
 
     // Skip to the last frame and clear.
-    decoder->setData(fullData.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(fullData));
+    decoder->setData(segmentReader.get(), true);
     EXPECT_EQ(frameCount, decoder->frameCount());
     ImageFrame* lastFrame = decoder->frameBufferAtIndex(frameCount - 1);
     EXPECT_EQ(baselineHashes[frameCount - 1], hashBitmap(lastFrame->getSkBitmap()));
     decoder->clearCacheExceptFrame(kNotFound);
 
     // Resume decoding of the first frame.
     ImageFrame* firstFrame = decoder->frameBufferAtIndex(0);
     EXPECT_EQ(ImageFrame::FrameComplete, firstFrame->status());
     EXPECT_EQ(baselineHashes[0], hashBitmap(firstFrame->getSkBitmap()));
 }
 
 // The first LZW codes in the image are invalid values that try to create a loop
 // in the dictionary. Decoding should fail, but not infinitely loop or corrupt memory.
 TEST(GIFImageDecoderTest, badInitialCode)
 {
     RefPtr<SharedBuffer> testData = readFile(decodersTestingDir, "bad-initial-code.gif");
     ASSERT_TRUE(testData.get());
 
     OwnPtr<ImageDecoder> testDecoder = createDecoder();
-    testDecoder->setData(testData.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(testData));
+    testDecoder->setData(segmentReader.get(), true);
     EXPECT_EQ(1u, testDecoder->frameCount());
     ASSERT_TRUE(testDecoder->frameBufferAtIndex(0));
     EXPECT_TRUE(testDecoder->failed());
 }
 
 // The image has an invalid LZW code that exceeds dictionary size. Decoding should fail.
 TEST(GIFImageDecoderTest, badCode)
 {
     RefPtr<SharedBuffer> testData = readFile(decodersTestingDir, "bad-code.gif");
     ASSERT_TRUE(testData.get());
 
     OwnPtr<ImageDecoder> testDecoder = createDecoder();
-    testDecoder->setData(testData.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(testData));
+    testDecoder->setData(segmentReader.get(), true);
     EXPECT_EQ(1u, testDecoder->frameCount());
     ASSERT_TRUE(testDecoder->frameBufferAtIndex(0));
     EXPECT_TRUE(testDecoder->failed());
 }
 
 TEST(GIFImageDecoderTest, invalidDisposalMethod)
 {
     OwnPtr<ImageDecoder> decoder = createDecoder();
 
     // The image has 2 frames, with disposal method 4 and 5, respectively.
     RefPtr<SharedBuffer> data = readFile(webTestsDataDir, "invalid-disposal-method.gif");
     ASSERT_TRUE(data.get());
-    decoder->setData(data.get(), true);
+    RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+    decoder->setData(segmentReader.get(), true);
 
     EXPECT_EQ(2u, decoder->frameCount());
     // Disposal method 4 is converted to ImageFrame::DisposeOverwritePrevious.
     EXPECT_EQ(ImageFrame::DisposeOverwritePrevious, decoder->frameBufferAtIndex(0)->disposalMethod());
     // Disposal method 5 is ignored.
     EXPECT_EQ(ImageFrame::DisposeNotSpecified, decoder->frameBufferAtIndex(1)->disposalMethod());
 }
 
 TEST(GIFImageDecoderTest, firstFrameHasGreaterSizeThanScreenSize)
 {
     RefPtr<SharedBuffer> fullData = readFile(decodersTestingDir, "first-frame-has-greater-size-than-screen-size.gif");
     ASSERT_TRUE(fullData.get());
 
     OwnPtr<ImageDecoder> decoder;
     IntSize frameSize;
 
     // Compute hashes when the file is truncated.
     for (size_t i = 1; i <= fullData->size(); ++i) {
         decoder = createDecoder();
         RefPtr<SharedBuffer> data = SharedBuffer::create(fullData->data(), i);
-        decoder->setData(data.get(), i == fullData->size());
+        RefPtr<SharedBufferSegmentReader> segmentReader = adoptRef(new SharedBufferSegmentReader(data));
+        decoder->setData(segmentReader.get(), i == fullData->size());
 
         if (decoder->isSizeAvailable() && !frameSize.width() && !frameSize.height()) {
             frameSize = decoder->decodedSize();
             continue;
         }
 
         ASSERT_EQ(frameSize.width(), decoder->decodedSize().width());
         ASSERT_EQ(frameSize.height(), decoder->decodedSize().height());
     }
 }
 
 } // namespace blink