Removing the dependency on GraphicsContext for drawing images in 2D canvas

Source/platform/graphics/skia/SkiaUtils.cpp

 /*
  * Copyright (c) 2006,2007,2008, 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 312 matching lines @@
         return InterpolationLow;
 
     // Everything else gets resampled.
     // High quality interpolation only enabled for scaling and translation.
     if (!(matrix.getType() & (SkMatrix::kAffine_Mask | SkMatrix::kPerspective_Mask)))
         return InterpolationHigh;
 
     return InterpolationLow;
 }
 
-
-bool shouldDrawAntiAliased(const GraphicsContext* context, const SkRect& destRect)
-{
-    if (!context->shouldAntialias())
-        return false;
-    const SkMatrix totalMatrix = context->getTotalMatrix();
-    // Don't disable anti-aliasing if we're rotated or skewed.
-    if (!totalMatrix.rectStaysRect())
-        return true;
-    // Disable anti-aliasing for scales or n*90 degree rotations.
-    // Allow to opt out of the optimization though for "hairline" geometry
-    // images - using the shouldAntialiasHairlineImages() GraphicsContext flag.
-    if (!context->shouldAntialiasHairlineImages())
-        return false;
-    // Check if the dimensions of the destination are "small" (less than one
-    // device pixel). To prevent sudden drop-outs. Since we know that
-    // kRectStaysRect_Mask is set, the matrix either has scale and no skew or
-    // vice versa. We can query the kAffine_Mask flag to determine which case
-    // it is.
-    // FIXME: This queries the CTM while drawing, which is generally
-    // discouraged. Always drawing with AA can negatively impact performance
-    // though - that's why it's not always on.
-    SkScalar widthExpansion, heightExpansion;
-    if (totalMatrix.getType() & SkMatrix::kAffine_Mask)
-        widthExpansion = totalMatrix[SkMatrix::kMSkewY], heightExpansion = totalMatrix[SkMatrix::kMSkewX];
-    else
-        widthExpansion = totalMatrix[SkMatrix::kMScaleX], heightExpansion = totalMatrix[SkMatrix::kMScaleY];
-    return destRect.width() * fabs(widthExpansion) < 1 || destRect.height() * fabs(heightExpansion) < 1;
-}
-
 int clampedAlphaForBlending(float alpha)
 {
     if (alpha < 0)
         return 0;
     int roundedAlpha = roundf(alpha * 256);
     if (roundedAlpha > 256)
         roundedAlpha = 256;
     return roundedAlpha;
 }
 
 SkColor scaleAlpha(SkColor color, float alpha)
 {
     return scaleAlpha(color, clampedAlphaForBlending(alpha));
 }
 
 SkColor scaleAlpha(SkColor color, int alpha)
 {
     int a = (SkColorGetA(color) * alpha) >> 8;
     return (color & 0x00FFFFFF) | (a << 24);
 }
 
 }  // namespace blink