Refactoring DrawLooper so that it can apply shadow effects as skia image filters

Source/core/platform/graphics/skia/NativeImageSkia.cpp

 /*
  * Copyright (c) 2008, 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 13 matching lines @@
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/platform/graphics/skia/NativeImageSkia.h"
 
+#include "core/platform/FloatConversion.h"
 #include "core/platform/PlatformInstrumentation.h"
 #include "core/platform/chromium/TraceEvent.h"
 #include "core/platform/graphics/FloatPoint.h"
 #include "core/platform/graphics/FloatRect.h"
 #include "core/platform/graphics/FloatSize.h"
 #include "core/platform/graphics/GraphicsContext.h"
 #include "core/platform/graphics/Image.h"
 #include "core/platform/graphics/chromium/DeferredImageDecoder.h"
 #include "core/platform/graphics/skia/SkiaUtils.h"
 #include "skia/ext/image_operations.h"
@@ skipping 275 matching lines @@
 {
     return !context->getTotalMatrix().rectStaysRect();
 }
 
 void NativeImageSkia::draw(GraphicsContext* context, const SkRect& srcRect, const SkRect& destRect, SkXfermode::Mode compOp) const
 {
     TRACE_EVENT0("skia", "NativeImageSkia::draw");
     SkPaint paint;
     paint.setXfermodeMode(compOp);
     paint.setAlpha(context->getNormalizedAlpha());
-    paint.setLooper(context->drawLooper());
+    DrawLooper* drawLooper = context->drawLooper();
+    if (drawLooper) {
+        if (drawLooper->shouldUseImageFilterToDrawBitmap(bitmap())) {
+            paint.setImageFilter(context->drawLooper()->imageFilter());
+        } else {
+            paint.setLooper(drawLooper->skDrawLooper());
+        }
+    }
     // only antialias if we're rotated or skewed
     paint.setAntiAlias(hasNon90rotation(context));
 
     ResamplingMode resampling;
     if (context->isAccelerated()) {
         resampling = LinearResampling;
     } else if (context->printing()) {
         resampling = NoResampling;
     } else {
         // Take into account scale applied to the canvas when computing sampling mode (e.g. CSS scale or page scale).
@@ skipping 196 matching lines @@
 SkIRect NativeImageSkia::ImageResourceInfo::rectInSubset(const SkIRect& otherScaledImageSubset)
 {
     if (!scaledImageSubset.contains(otherScaledImageSubset))
         return SkIRect::MakeEmpty();
     SkIRect subsetRect = otherScaledImageSubset;
     subsetRect.offset(-scaledImageSubset.x(), -scaledImageSubset.y());
     return subsetRect;
 }
 
 } // namespace WebCore