Use alignas to force alignment.

src/core/SkSmallAllocator.h

Index: src/core/SkSmallAllocator.h
diff --git a/src/core/SkSmallAllocator.h b/src/core/SkSmallAllocator.h
index 9095fa57fc11fde0022c023f5e8341d7dae819dd..67afe756912bdd014945f0ba235dc9797cdc3aa7 100644
--- a/src/core/SkSmallAllocator.h
+++ b/src/core/SkSmallAllocator.h
@@ -93,7 +93,7 @@ public:
             // There is space in fStorage.
             rec->fStorageSize = storageRequired;
             rec->fHeapStorage = nullptr;
-            rec->fObj = static_cast<void*>(fStorage.fBytes + fStorageUsed);
+            rec->fObj = static_cast<void*>(fStorage + fStorageUsed);
             fStorageUsed += storageRequired;
         }
         rec->fKillProc = DestroyT<T>;
@@ -129,17 +129,11 @@ private:
         static_cast<T*>(ptr)->~T();
     }
 
-    struct SK_STRUCT_ALIGN(16) Storage {
-        // we add kMaxObjects * 15 to account for the worst-case slop, where each allocation wasted
-        // 15 bytes (due to forcing each to be 16-byte aligned)
-        char    fBytes[kTotalBytes + kMaxObjects * 15];
-    };
-
-    Storage     fStorage;
+    alignas(16) char fStorage[kTotalBytes];
     // Number of bytes used so far.
-    size_t      fStorageUsed;
-    uint32_t    fNumObjects;
-    Rec         fRecs[kMaxObjects];
+    size_t   fStorageUsed;
+    uint32_t fNumObjects;
+    Rec      fRecs[kMaxObjects];
 };
 
 #endif // SkSmallAllocator_DEFINED