Implement Dump-on-DCHECK (via a new LogSeverity).

base/allocator/partition_allocator/partition_alloc.h

Index: base/allocator/partition_allocator/partition_alloc.h
diff --git a/base/allocator/partition_allocator/partition_alloc.h b/base/allocator/partition_allocator/partition_alloc.h
index 15a501ae6f6073b020aa3cf4ce0511b6ffc08986..36894ad1e194f1e9a1beba01c2a2a1020b78360c 100644
--- a/base/allocator/partition_allocator/partition_alloc.h
+++ b/base/allocator/partition_allocator/partition_alloc.h
@@ -507,7 +507,7 @@ ALWAYS_INLINE size_t PartitionCookieSizeAdjustAdd(size_t size) {
   // Add space for cookies, checking for integer overflow. TODO(palmer):
   // Investigate the performance and code size implications of using
   // CheckedNumeric throughout PA.
-  DCHECK(size + (2 * kCookieSize) > size);
+  CHECK(size + (2 * kCookieSize) > size);

[Nico, 2017/01/17 13:03:41]

You lost me in the first file already. Why do we have a CHECK() in a
DCHECK_IS_ON #if? Even if it's intentional for some reason, that looks like a
bug.

   size += 2 * kCookieSize;
 #endif
   return size;