[PartitionAlloc] Disable periodic purge for non-DCHECK() builds on Windows.

This is possibly the cause of browser process crashes on
Windows. Disable it only on this platform to ease investigation.

Bug: 1155905
Change-Id: I6a5330479cb701c4b74da1986c2620d41056960c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2582018Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Reviewed-by: Arthur Sonzogni <arthursonzogni@chromium.org>
Commit-Queue: Benoit L <lizeb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#835203}

content/app/content_main_runner_impl.cc

@@ -1011,7 +1011,11 @@ int ContentMainRunnerImpl::RunBrowser(MainFunctionParams& main_params,
   // Enable PCScan once we are certain that FeatureList was initialized.
   EnablePCScanForMallocPartitionsIfNeeded();
 
-#if BUILDFLAG(USE_PARTITION_ALLOC_AS_MALLOC)
+  // This is only relevant for PartitionAlloc-Everywhere builds.
+  // Temporarily disabled for non-DCHECK() builds on Windows, due to possibly
+  // related crashes (crbug.com/1155905).
+#if BUILDFLAG(USE_PARTITION_ALLOC_AS_MALLOC) && \
+    !(defined(OS_WIN) && !DCHECK_IS_ON())
   base::internal::ThreadCacheRegistry::Instance().StartPeriodicPurge();
 #endif