Simplify flattening to just write enough to call the factory

src/core/SkImageFilter.cpp

 /*
  * Copyright 2012 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkImageFilter.h"
 
 #include "SkBitmap.h"
@@ skipping 57 matching lines @@
     sk_bzero(fInputs.get(), size);
 }
 
 void SkImageFilter::Common::detachInputs(SkImageFilter** inputs) {
     const size_t size = fInputs.count() * sizeof(SkImageFilter*);
     memcpy(inputs, fInputs.get(), size);
     sk_bzero(fInputs.get(), size);
 }
 
 bool SkImageFilter::Common::unflatten(SkReadBuffer& buffer, int expectedCount) {
-    int count = buffer.readInt();
-    if (expectedCount < 0) {    // means the caller doesn't care how many
-        expectedCount = count;
+    const int count = buffer.readInt();
+    if (!buffer.validate(count >= 0)) {

[sugoi1, 2014/08/19 18:46:16]

If it is no longer possible to use an expectedCount with a value of -1, then
this is also checked at line 82, so I think you can remove lines 79 to 81. Also,
we could consider making expectedCount an unsigned value.

If it is still possible to use an expectedCount with a value of -1, then this is
broken, since it will always fail the validation at line 82.

[reed1, 2014/08/19 19:58:05]

Good catch, I think I no longer take -1.

+        return false;
     }
     if (!buffer.validate((count == expectedCount) && (count >= 0))) {
         return false;
     }
 
     this->allocInputs(count);
     for (int i = 0; i < count; i++) {
         if (buffer.readBool()) {
             fInputs[i] = buffer.readImageFilter();
         }
@@ skipping 401 matching lines @@
 } // namespace
 
 SkImageFilter::Cache* SkImageFilter::Cache::Create(size_t maxBytes) {
     return SkNEW_ARGS(CacheImpl, (maxBytes));
 }
 
 SkImageFilter::Cache* SkImageFilter::Cache::Get() {
     SK_DECLARE_STATIC_LAZY_PTR(SkImageFilter::Cache, cache, CreateCache);
     return cache.get();
 }