Revert of change SkDraw and all Blitters to use pixmap instead of bitmap

src/effects/SkLayerRasterizer.cpp

Index: src/effects/SkLayerRasterizer.cpp
diff --git a/src/effects/SkLayerRasterizer.cpp b/src/effects/SkLayerRasterizer.cpp
index 8403d06147a602969aeb8c5f5d1af00a3fe062f5..d3e112c3a4b836118be46258c5f3d1b9fb181ab3 100644
--- a/src/effects/SkLayerRasterizer.cpp
+++ b/src/effects/SkLayerRasterizer.cpp
@@ -116,12 +116,9 @@
     }
 
     if (SkMask::kJustComputeBounds_CreateMode != mode) {
+        SkBitmap        device;
+        SkRasterClip    rectClip;
         SkDraw          draw;
-        if (!draw.fDst.reset(*mask)) {
-            return false;
-        }
-
-        SkRasterClip    rectClip;
         SkMatrix        translatedMatrix;  // this translates us to our local pixels
         SkMatrix        drawMatrix;        // this translates the path by each layer's offset
 
@@ -131,6 +128,9 @@
         translatedMatrix.postTranslate(-SkIntToScalar(mask->fBounds.fLeft),
                                        -SkIntToScalar(mask->fBounds.fTop));
 
+        device.installMaskPixels(*mask);
+
+        draw.fBitmap    = &device;
         draw.fMatrix    = &drawMatrix;
         draw.fRC        = &rectClip;
         draw.fClip      = &rectClip.bwRgn();