Simplify flattening to just write enough to call the factory

src/effects/SkBlurImageFilter.cpp

Index: src/effects/SkBlurImageFilter.cpp
diff --git a/src/effects/SkBlurImageFilter.cpp b/src/effects/SkBlurImageFilter.cpp
index 5c3ff493c27ebae1eee6ed1c301e7280b8dd8a63..76cb0b14ef46fdf2b33ba6411c2365e7d205d711 100644
--- a/src/effects/SkBlurImageFilter.cpp
+++ b/src/effects/SkBlurImageFilter.cpp
@@ -23,6 +23,7 @@
 // raster paths.
 #define MAX_SIGMA SkIntToScalar(532)
 
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
 SkBlurImageFilter::SkBlurImageFilter(SkReadBuffer& buffer)
   : INHERITED(1, buffer) {
     fSigma.fWidth = buffer.readScalar();
@@ -40,9 +41,20 @@ SkBlurImageFilter::SkBlurImageFilter(SkScalar sigmaX,
     : INHERITED(1, &input, cropRect), fSigma(SkSize::Make(sigmaX, sigmaY)) {
     SkASSERT(sigmaX >= 0 && sigmaY >= 0);
 }
+#endif
+
+SkFlattenable* SkBlurImageFilter::CreateProc(SkReadBuffer& buffer) {
+    Common common;
+    if (!common.unflatten(buffer, 1)) {
+        return NULL;
+    }
+    SkScalar sigmaX = buffer.readScalar();
+    SkScalar sigmaY = buffer.readScalar();
+    return Create(sigmaX, sigmaY, common.inputAt(0), &common.cropRect());
+}
 
 void SkBlurImageFilter::flatten(SkWriteBuffer& buffer) const {
-    this->INHERITED::flatten(buffer);
+    this->flattenCommon(buffer);
     buffer.writeScalar(fSigma.fWidth);
     buffer.writeScalar(fSigma.fHeight);
 }