Remove uses of SkBitmap::Config (deprecated) from core/ and platform/.

Source/platform/graphics/ImageFrameGeneratorTest.cpp

Index: Source/platform/graphics/ImageFrameGeneratorTest.cpp
diff --git a/Source/platform/graphics/ImageFrameGeneratorTest.cpp b/Source/platform/graphics/ImageFrameGeneratorTest.cpp
index 3ea48d0cb1e36c8ebfb2ebe3c2a33db5e88904b3..ff1fc88d8cdde9bf27a8777727f35ddeb300e4f0 100644
--- a/Source/platform/graphics/ImageFrameGeneratorTest.cpp
+++ b/Source/platform/graphics/ImageFrameGeneratorTest.cpp
@@ -92,8 +92,7 @@ protected:
     PassOwnPtr<ScaledImageFragment> createCompleteImage(const SkISize& size)
     {
         SkBitmap bitmap;
-        bitmap.setConfig(SkBitmap::kARGB_8888_Config, size.width(), size.height());
-        bitmap.allocPixels();
+        bitmap.allocN32Pixels(size.width(), size.height());
         return ScaledImageFragment::createComplete(size, 0, bitmap);
     }