Revert of ensure that we call onUnlock only when we onLock succeeded

src/lazy/SkCachingPixelRef.cpp

Index: src/lazy/SkCachingPixelRef.cpp
diff --git a/src/lazy/SkCachingPixelRef.cpp b/src/lazy/SkCachingPixelRef.cpp
index b7eaf574aac436223220923d7cd00fab2faa66af..667a94931b1a33fe59b14d53f9990eb084fe8214 100644
--- a/src/lazy/SkCachingPixelRef.cpp
+++ b/src/lazy/SkCachingPixelRef.cpp
@@ -90,7 +90,9 @@
 }
 
 void SkCachingPixelRef::onUnlockPixels() {
-    SkASSERT(fScaledCacheId != NULL);
-    SkScaledImageCache::Unlock( static_cast<SkScaledImageCache::ID*>(fScaledCacheId));
-    fScaledCacheId = NULL;
+    if (fScaledCacheId != NULL) {
+        SkScaledImageCache::Unlock(
+            static_cast<SkScaledImageCache::ID*>(fScaledCacheId));
+        fScaledCacheId = NULL;
+    }
 }