Early reporting of opaqueness by decoders.

third_party/WebKit/Source/platform/image-decoders/jpeg/JPEGImageDecoderTest.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 263 matching lines @@
 // This test verifies that calling SharedBuffer::mergeSegmentsIntoBuffer() does
 // not break JPEG decoding at a critical point: in between a call to decode the
 // size (when JPEGImageDecoder stops while it may still have input data to
 // read) and a call to do a full decode.
 TEST(JPEGImageDecoderTest, mergeBuffer)
 {
     const char* jpegFile = "/LayoutTests/fast/images/resources/lenna.jpg";
     testMergeBuffer(&createDecoder, jpegFile);
 }
 
+TEST(JPEGImageDecoderTest, hasAlphaAtIndex)
+{
+    const char* jpegFile = "/LayoutTests/fast/images/resources/lenna.jpg";
+    RefPtr<SharedBuffer> data = readFile(jpegFile);
+    ASSERT_TRUE(data);
+
+    OwnPtr<ImageDecoder> decoder = createDecoder();
+    EXPECT_TRUE(decoder->frameHasAlphaAtIndex(0));
+
+    decoder->setData(data.get(), false);
+    EXPECT_TRUE(decoder->frameHasAlphaAtIndex(0));
+    EXPECT_TRUE(decoder->frameHasAlphaAtIndex(1));
+
+    decoder->setData(data.get(), true);
+    EXPECT_FALSE(decoder->frameHasAlphaAtIndex(0));
+    EXPECT_TRUE(decoder->frameHasAlphaAtIndex(1));
+}
+
 } // namespace blink