Add missing ENABLE_TAG_FOR_CHECKED_PTR2

Bug: 1073933
Change-Id: Iff307d9955f43827fe21cb137b032a5fda440909
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2287330
Commit-Queue: Bartek Nowierski <bartekn@chromium.org>
Commit-Queue: Kentaro Hara <haraken@chromium.org>
Auto-Submit: Bartek Nowierski <bartekn@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#786209}

base/memory/checked_ptr.cc

@@ -9,7 +9,8 @@
 namespace base {
 namespace internal {
 
-#if defined(ARCH_CPU_64_BITS) && !defined(OS_NACL)
+#if defined(ARCH_CPU_64_BITS) && !defined(OS_NACL) && \
+    ENABLE_TAG_FOR_CHECKED_PTR2
 
 BASE_EXPORT bool CheckedPtr2ImplPartitionAllocSupport::EnabledForPtr(
     void* ptr) {

base/memory/checked_ptr.h

@@ -79,7 +79,8 @@ struct CheckedPtrNoOpImpl {
   static ALWAYS_INLINE void IncrementSwapCountForTest() {}
 };
 
-#if defined(ARCH_CPU_64_BITS) && !defined(OS_NACL)
+#if defined(ARCH_CPU_64_BITS) && !defined(OS_NACL) && \
+    ENABLE_TAG_FOR_CHECKED_PTR2
 
 constexpr int kValidAddressBits = 48;
 constexpr uintptr_t kAddressMask = (1ull << kValidAddressBits) - 1;
@@ -300,7 +301,8 @@ struct CheckedPtr2Impl {
   static constexpr uintptr_t kWrappedNullPtr = 0;
 };
 
-#endif  // defined(ARCH_CPU_64_BITS) && !defined(OS_NACL)
+#endif  // defined(ARCH_CPU_64_BITS) && !defined(OS_NACL) &&
+        // ENABLE_TAG_FOR_CHECKED_PTR2
 
 template <typename T>
 struct DereferencedPointerType {