asan/win: Unbreak build after https://codereview.chromium.org/2008553007/

..\..\courgette\third_party\bsdiff\paged_array_unittest.cc(20,11):
  error: unused variable 'kIterations' [-Werror,-Wunused-const-variable]
const int kIterations = 20;
          ^
..\..\courgette\third_party\bsdiff\paged_array_unittest.cc(21,11):
  error: unused variable 'kSizeBig' [-Werror,-Wunused-const-variable]
const int kSizeBig = 200 * 1024 * 1024 / sizeof(int);  // 200MB
          ^

BUG=82385
TBR=huangs

Review-Url: https://codereview.chromium.org/2036393002
Cr-Commit-Position: refs/heads/master@{#397810}

courgette/third_party/bsdiff/paged_array_unittest.cc

@@ -15,10 +15,12 @@
 
 namespace {
 
+#if !defined(ADDRESS_SANITIZER) || !defined(OS_WIN)
 // Total allocation of 4GB will fail in 32 bit programs if allocations are
 // leaked.
 const int kIterations = 20;
 const int kSizeBig = 200 * 1024 * 1024 / sizeof(int);  // 200MB
+#endif
 
 const size_t kLogBlockSizeSmall = 10;
 const size_t kBlockSizeSmall = 1 << kLogBlockSizeSmall;