Clean up SkImageFilter constructors.

src/effects/SkMergeImageFilter.cpp

Index: src/effects/SkMergeImageFilter.cpp
diff --git a/src/effects/SkMergeImageFilter.cpp b/src/effects/SkMergeImageFilter.cpp
index adf9afe9b3dd100d5c276f509931b74857ab22ed..4022da3096d4c49a9696991b9c0a6172c32c42c6 100755
--- a/src/effects/SkMergeImageFilter.cpp
+++ b/src/effects/SkMergeImageFilter.cpp
@@ -40,17 +40,6 @@ void SkMergeImageFilter::initModes(const SkXfermode::Mode modes[]) {
     }
 }
 
-SkMergeImageFilter::SkMergeImageFilter(SkImageFilter* first, SkImageFilter* second,
-                                       SkXfermode::Mode mode,
-                                       const CropRect* cropRect) : INHERITED(first, second, cropRect) {
-    if (SkXfermode::kSrcOver_Mode != mode) {
-        SkXfermode::Mode modes[] = { mode, mode };
-        this->initModes(modes);
-    } else {
-        fModes = NULL;
-    }
-}
-
 SkMergeImageFilter::SkMergeImageFilter(SkImageFilter* filters[], int count,
                                        const SkXfermode::Mode modes[],
                                        const CropRect* cropRect) : INHERITED(count, filters, cropRect) {