Merge 93441 - REGRESSION(r91628): 3 canvas tests crash on Chromium Linux and one test fail on Chr...

Merge 93441 - REGRESSION(r91628): 3 canvas tests crash on Chromium Linux and one test fail on Chromium Mac
https://bugs.webkit.org/show_bug.cgi?id=65063

Reviewed by Darin Fisher.

Fixes crashes due to a bad cast from Image to BitmapImage on skia ports
that use BitmapImageSingleFrameSkia. In the skia port
Image::isBitmapImage() returning true does not necessarily mean that
Image is of type BitmapImage.

Covered by fast/canvas/canvas-as-image.html and many other canvas
tests.

Patch originally by Tom Hudson.

* platform/graphics/BitmapImage.h:
(WebCore::BitmapImage::currentFrameHasAlpha):
(WebCore::BitmapImage::notSolidColor):
* platform/graphics/Image.cpp:
(WebCore::Image::drawTiled):
* platform/graphics/Image.h:
(WebCore::Image::currentFrameHasAlpha):
(WebCore::Image::notSolidColor):
* platform/graphics/skia/BitmapImageSingleFrameSkia.h:
(WebCore::BitmapImageSingleFrameSkia::currentFrameHasAlpha):
(WebCore::BitmapImageSingleFrameSkia::notSolidColor):
* rendering/RenderImage.cpp:
(WebCore::RenderImage::backgroundIsObscured):

BUG=93558
TBR=jamesr@google.com
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=93493