Initial error handling code

src/core/SkOrderedWriteBuffer.cpp

Index: src/core/SkOrderedWriteBuffer.cpp
diff --git a/src/core/SkOrderedWriteBuffer.cpp b/src/core/SkOrderedWriteBuffer.cpp
index 64f52193acaf7c55dab611a5b53f41f13685fd7e..8904d7cde1f9f36bdb8c09ffc7fc6c32dff8c3bd 100644
--- a/src/core/SkOrderedWriteBuffer.cpp
+++ b/src/core/SkOrderedWriteBuffer.cpp
@@ -270,7 +270,9 @@ void SkOrderedWriteBuffer::writeFlattenable(SkFlattenable* flattenable) {
         factory = flattenable->getFactory();
     }
     if (NULL == factory) {
-        if (fFactorySet != NULL || fNamedFactorySet != NULL) {
+        if (this->isValidating()) {
+            this->writeString(NULL);
+        } else if (fFactorySet != NULL || fNamedFactorySet != NULL) {
             this->write32(0);
         } else {
             this->writeFunctionPtr(NULL);
@@ -290,7 +292,14 @@ void SkOrderedWriteBuffer::writeFlattenable(SkFlattenable* flattenable) {
      *      name. SkGPipe uses this technique so it can write the name to its
      *      stream before writing the flattenable.
      */
-    if (fFactorySet) {
+    if (this->isValidating()) {
+        const char* name = SkFlattenable::FactoryToName(factory);
+        this->writeString(name);
+        if (NULL == name) {
+            SkASSERT(!"Missing factory name");
+            return;
+        }
+    } else if (fFactorySet) {
         this->write32(fFactorySet->add(factory));
     } else if (fNamedFactorySet) {
         int32_t index = fNamedFactorySet->find(factory);