Enable flattening/unflattening with custom unflatten procs

src/core/SkReadBuffer.cpp

Index: src/core/SkReadBuffer.cpp
diff --git a/src/core/SkReadBuffer.cpp b/src/core/SkReadBuffer.cpp
index abd46312f747e80e744f636d15cadb7672fa925d..752b83a3f5d22d96faa0ab1ae7e623236c1d0b7e 100644
--- a/src/core/SkReadBuffer.cpp
+++ b/src/core/SkReadBuffer.cpp
@@ -332,21 +332,40 @@ SkFlattenable* SkReadBuffer::readFlattenable(SkFlattenable::Type ft) {
 
     SkFlattenable::Factory factory = nullptr;
 
+    uint32_t index = fReader.readU32();
+    if (0 == index) {
+        return nullptr; // writer failed to give us the flattenable
+    }
+
     if (fFactoryCount > 0) {
-        int32_t index = fReader.readU32();
-        if (0 == index) {
-            return nullptr; // writer failed to give us the flattenable
-        }
         index -= 1;     // we stored the index-base-1
-        if ((unsigned)index >= (unsigned)fFactoryCount) {
+        if (index >= (uint32_t) fFactoryCount) {
             this->validate(false);
             return nullptr;
         }
         factory = fFactoryArray[index];
     } else {
-        factory = (SkFlattenable::Factory)readFunctionPtr();
-        if (nullptr == factory) {
-            return nullptr; // writer failed to give us the flattenable
+        SkString name;
+        SkString* namePtr = fFlattenableDict.find(index);
+        if (namePtr) {
+            // Assume we have already seen this name and saved it to the dict.
+            name = *namePtr;
+        } else {
+            // The string must be passed after the index.
+            this->readString(&name);
+
+            // Add the string to the dictionary.
+            fFlattenableDict.set(index, name);
+        }
+
+        // Check if a custom Factory has been specified for this flattenable.
+        factory = getCustomFactory(name);

[mtklein, 2016/04/19 18:14:55]

this->

[msarett, 2016/04/19 18:55:51]

Done.

+        if (!factory) {
+            // If there is no custom Factory, check for a default.
+            factory = SkFlattenable::NameToFactory(name.c_str());
+            if (!factory) {
+                return nullptr; // writer failed to give us the flattenable
+            }
         }
     }