Remove SK_SUPPORT_LEGACY_DEEPFLATTENING.

src/effects/SkMergeImageFilter.cpp

Index: src/effects/SkMergeImageFilter.cpp
diff --git a/src/effects/SkMergeImageFilter.cpp b/src/effects/SkMergeImageFilter.cpp
index 9e7f4e543c743f9cc1afb5f98c30ece44cff8ab8..d932d3ccce50a05ffd5689cece10a926d3a16ada 100755
--- a/src/effects/SkMergeImageFilter.cpp
+++ b/src/effects/SkMergeImageFilter.cpp
@@ -140,24 +140,3 @@ void SkMergeImageFilter::flatten(SkWriteBuffer& buffer) const {
         buffer.writeByteArray(fModes, countInputs() * sizeof(fModes[0]));
     }
 }
-
-#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
-SkMergeImageFilter::SkMergeImageFilter(SkReadBuffer& buffer)
-  : INHERITED(-1, buffer) {
-    bool hasModes = buffer.readBool();
-    if (hasModes) {
-        this->initAllocModes();
-        int nbInputs = countInputs();
-        size_t size = nbInputs * sizeof(fModes[0]);
-        SkASSERT(buffer.getArrayCount() == size);
-        if (buffer.validate(buffer.getArrayCount() == size) &&
-            buffer.readByteArray(fModes, size)) {
-            for (int i = 0; i < nbInputs; ++i) {
-                buffer.validate(SkIsValidMode((SkXfermode::Mode)fModes[i]));
-            }
-        }
-    } else {
-        fModes = 0;
-    }
-}
-#endif