Blink image-decoders: (lazy) deferred image decoding support for ICO

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 68 matching lines @@
         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);
-        if (frame && frame->getStatus() == ImageFrame::FrameComplete && framesDecoded < frameCount)
-            ++framesDecoded;
+        for (size_t i = framesDecoded; i < frameCount; ++i) {
+            // In ICOImageDecoder memory layout could differ from frame order.
+            // E.g. memory layout could be |<frame1><frame0>| and frameCount
+            // would return 1 until receiving full file.
+            // When file is completely received frameCount would return 2 and
+            // only then both frames could be completely decoded.
+            ImageFrame* frame = decoder->frameBufferAtIndex(i);
+            if (frame && frame->getStatus() == ImageFrame::FrameComplete)
+                ++framesDecoded;
+        }
     }
 
     EXPECT_FALSE(decoder->failed());
     EXPECT_EQ(expectedFrameCount, decoder->frameCount());
     EXPECT_EQ(expectedFrameCount, framesDecoded);
     EXPECT_EQ(expectedRepetitionCount, decoder->repetitionCount());
 
     ASSERT_EQ(expectedFrameCount, baselineHashes.size());
     for (size_t i = 0; i < decoder->frameCount(); i++) {
         ImageFrame* frame = decoder->frameBufferAtIndex(i);
@@ skipping 30 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->getStatus(), ImageFrame::FrameComplete);
     EXPECT_EQ(hashBitmap(frame->bitmap()), hash);
 }
 
 } // namespace blink