fix build by using ifdef instead of if for SK_DEBUG

src/core/SkResourceCache.cpp

Index: src/core/SkResourceCache.cpp
diff --git a/src/core/SkResourceCache.cpp b/src/core/SkResourceCache.cpp
index bacb8158aa683b628f2054f578eaab3256e40c5a..6e3ad830009ba545778badf819a6862d5c8bc720 100644
--- a/src/core/SkResourceCache.cpp
+++ b/src/core/SkResourceCache.cpp
@@ -549,7 +549,7 @@ static void cleanup_gResourceCache() {
     // Chrome seems to have funky multi-process things going on in unit tests that
     // makes this unsafe to delete when the main process atexit()s.
     // SkLazyPtr does the same sort of thing.
-#if SK_DEBUG
+#ifdef SK_DEBUG
     delete gResourceCache;
 #endif
 }