change old picture serialization to really handle images

src/core/SkPixelRef.cpp

Index: src/core/SkPixelRef.cpp
diff --git a/src/core/SkPixelRef.cpp b/src/core/SkPixelRef.cpp
index cfe93fda5883713144ff51b083a5bda6b26e85f5..6e1f5c6417277aca9bedbdcc8da533a23f2321c9 100644
--- a/src/core/SkPixelRef.cpp
+++ b/src/core/SkPixelRef.cpp
@@ -259,6 +259,10 @@ bool SkPixelRef::requestLock(const LockRequest& request, LockResult* result) {
     if (request.fSize.isEmpty()) {
         return false;
     }
+    // until we support subsets, we have to check this...
+    if (request.fSize.width() != fInfo.width() || request.fSize.height() != fInfo.height()) {
+        return false;
+    }
 
     if (fPreLocked) {
         result->fUnlockProc = NULL;