Simplify flattening to just write enough to call the factory

src/effects/SkColorFilterImageFilter.cpp

Index: src/effects/SkColorFilterImageFilter.cpp
diff --git a/src/effects/SkColorFilterImageFilter.cpp b/src/effects/SkColorFilterImageFilter.cpp
index 2c3706769fa400a91e8ffdf3aa9a1e03c097e2e1..007890467f982933908313d4d475a3579351d9f8 100755
--- a/src/effects/SkColorFilterImageFilter.cpp
+++ b/src/effects/SkColorFilterImageFilter.cpp
@@ -83,14 +83,30 @@ SkColorFilterImageFilter::SkColorFilterImageFilter(SkColorFilter* cf,
     SkSafeRef(cf);
 }
 
+#ifdef SK_SUPPORT_LEGACY_DEEPFLATTENING
 SkColorFilterImageFilter::SkColorFilterImageFilter(SkReadBuffer& buffer)
   : INHERITED(1, buffer) {
     fColorFilter = buffer.readColorFilter();
 }
+#endif
 
-void SkColorFilterImageFilter::flatten(SkWriteBuffer& buffer) const {
-    this->INHERITED::flatten(buffer);
+SkFlattenable* SkColorFilterImageFilter::CreateProc(SkReadBuffer& buffer) {
+    Common common;
+    if (!common.unflatten(buffer)) {
+        return NULL;
+    }
+
+    SkAutoTUnref<SkColorFilter> cf(buffer.readColorFilter());
+    if (common.inputCount() > 1 || NULL == cf.get()) {

[Stephen White, 2014/07/17 21:29:00]

Nit: if we did pass the expected count to Common's constructor (or unflatten),
we wouldn't need to check it here.

[reed1, 2014/07/18 13:40:30]

The input-filter appears to be optional, reading the constructor on line 60. Is
that not the case?

[Stephen White, 2014/07/18 14:06:20]

Yes, it's optional, in the sense that it can be NULL, but the array should be of
size 1. We call getInput(0) unconditionally during processing (as do all the
filters), and getInput() asserts on out-of-bounds. In fact, I think it's quite
important that we make the expectedCount arg of Common::unflatten() non-default,
as it was before, for this reason.

+        buffer.validate(false);
+        return NULL;
+    }
+    SkImageFilter* imf = common.inputCount() ? common.inputs()[0] : NULL;
+    return Create(cf, imf, &common.cropRect());
+}
 
+void SkColorFilterImageFilter::flatten(SkWriteBuffer& buffer) const {
+    this->flattenCommon(buffer);
     buffer.writeFlattenable(fColorFilter);
 }