Passing alpha to DeferredImageDecoder once decoding completes

Passing alpha to DeferredImageDecoder once decoding completes
https://bugs.webkit.org/show_bug.cgi?id=108892

Patch by Min Qin <qinmin@chromium.org> on 2013-02-14
Reviewed by Stephen White.

Source/WebCore:

We should pass hasAlpha value back to the DeferredImageDecoder once decoding is completed
Added unit tests in ImageFrameGeneratorTest.

* platform/graphics/chromium/DeferredImageDecoder.cpp:
(WebCore::DeferredImageDecoder::frameHasAlphaAtIndex):
* platform/graphics/chromium/ImageFrameGenerator.cpp:
(WebCore::ImageFrameGenerator::tryToScale):
(WebCore::ImageFrameGenerator::decode):
* platform/graphics/chromium/LazyDecodingPixelRef.cpp:
(WebCore::LazyDecodingPixelRef::LazyDecodingPixelRef):
(WebCore::LazyDecodingPixelRef::onUnlockPixels):
* platform/graphics/chromium/LazyDecodingPixelRef.h:
(WebCore::LazyDecodingPixelRef::hasAlpha):
(LazyDecodingPixelRef):
* platform/graphics/chromium/ScaledImageFragment.cpp:
(WebCore::ScaledImageFragment::ScaledImageFragment):
* platform/graphics/chromium/ScaledImageFragment.h:
(WebCore::ScaledImageFragment::create):
(ScaledImageFragment):
(WebCore::ScaledImageFragment::hasAlpha):

Source/WebKit/chromium:

Add test to check that alpha value is passed from the decoder to ImageFrameGenerator.

* tests/ImageFrameGeneratorTest.cpp:
(WebCore::MockImageDecoderFactory::create):
(WebCore::TEST_F):
* tests/MockImageDecoder.h:
(WebCore::MockImageDecoder::MockImageDecoder):
(WebCore::MockImageDecoder::setFrameHasAlpha):
(MockImageDecoder):
(WebCore::MockImageDecoder::frameHasAlphaAtIndex):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@142891 268f45cc-cd09-0410-ab3c-d52691b4dbfc