Revert of add ImageShader, sharing code with its Bitmap cousin

src/image/SkImage_Raster.cpp

Index: src/image/SkImage_Raster.cpp
diff --git a/src/image/SkImage_Raster.cpp b/src/image/SkImage_Raster.cpp
index 18d6ba6fd7ffecb33342fc530efbcd49912c260f..67498f0e112cf4a5e2f001258906fc6c323316a1 100644
--- a/src/image/SkImage_Raster.cpp
+++ b/src/image/SkImage_Raster.cpp
@@ -80,6 +80,10 @@
 
     SkPixelRef* getPixelRef() const { return fBitmap.pixelRef(); }
 
+    SkShader* onNewShader(SkShader::TileMode,
+                          SkShader::TileMode,
+                          const SkMatrix* localMatrix) const override;
+
     bool isOpaque() const override;
     bool onAsLegacyBitmap(SkBitmap*, LegacyBitmapMode) const override;
 
@@ -139,6 +143,11 @@
 }
 
 SkImage_Raster::~SkImage_Raster() {}
+
+SkShader* SkImage_Raster::onNewShader(SkShader::TileMode tileX, SkShader::TileMode tileY,
+                                      const SkMatrix* localMatrix) const {
+    return SkShader::CreateBitmapShader(fBitmap, tileX, tileY, localMatrix);
+}
 
 SkSurface* SkImage_Raster::onNewSurface(const SkImageInfo& info, const SkSurfaceProps& props) const {
     return SkSurface::NewRaster(info, &props);