Require SK_DECLARE_STATIC_LAZY_PTR is used in global scope.

src/lazy/SkDiscardableMemoryPool.cpp

Index: src/lazy/SkDiscardableMemoryPool.cpp
diff --git a/src/lazy/SkDiscardableMemoryPool.cpp b/src/lazy/SkDiscardableMemoryPool.cpp
index f8f44d0c07cb2869b92a55ee2e0f047e9808a6fc..96d6046f3fb6c4f6e80eff1d8cf91a22b06dd946 100644
--- a/src/lazy/SkDiscardableMemoryPool.cpp
+++ b/src/lazy/SkDiscardableMemoryPool.cpp
@@ -260,8 +260,9 @@ SkDiscardableMemoryPool* SkDiscardableMemoryPool::Create(size_t size, SkBaseMute
     return SkNEW_ARGS(DiscardableMemoryPool, (size, mutex));
 }
 
+SK_DECLARE_STATIC_LAZY_PTR(SkDiscardableMemoryPool, global, create_global_pool);
+
 SkDiscardableMemoryPool* SkGetGlobalDiscardableMemoryPool() {
-    SK_DECLARE_STATIC_LAZY_PTR(SkDiscardableMemoryPool, global, create_global_pool);
     return global.get();
 }