Index: lib/sanitizer_common/sanitizer_allocator_primary64.h
===================================================================
--- lib/sanitizer_common/sanitizer_allocator_primary64.h
+++ lib/sanitizer_common/sanitizer_allocator_primary64.h
@@ -72,11 +72,10 @@
   void Init(s32 release_to_os_interval_ms) {
     uptr TotalSpaceSize = kSpaceSize + AdditionalSize();
     if (kUsingConstantSpaceBeg) {
-      CHECK_EQ(kSpaceBeg, reinterpret_cast<uptr>(
-                              MmapFixedNoAccess(kSpaceBeg, TotalSpaceSize)));
+      CHECK_EQ(kSpaceBeg, address_range.Init(TotalSpaceSize, AllocatorName(),
+                                             kSpaceBeg));
     } else {
-      NonConstSpaceBeg =
-          reinterpret_cast<uptr>(MmapNoAccess(TotalSpaceSize));
+      NonConstSpaceBeg = address_range.Init(TotalSpaceSize, AllocatorName());
       CHECK_NE(NonConstSpaceBeg, ~(uptr)0);
     }
     SetReleaseToOSIntervalMs(release_to_os_interval_ms);
@@ -544,6 +543,9 @@
  private:
   friend class MemoryMapper;
 
+  ReservedAddressRange address_range;
+  static const char *AllocatorName() { return "sanitizer_allocator"; }
+
   static const uptr kRegionSize = kSpaceSize / kNumClassesRounded;
   // FreeArray is the array of free-d chunks (stored as 4-byte offsets).
   // In the worst case it may reguire kRegionSize/SizeClassMap::kMinSize
@@ -625,7 +627,7 @@
   }
 
   bool MapWithCallback(uptr beg, uptr size) {
-    uptr mapped = reinterpret_cast<uptr>(MmapFixedOrDieOnFatalError(beg, size));
+    uptr mapped = address_range.Map(beg, size);
     if (UNLIKELY(!mapped))
       return false;
     CHECK_EQ(beg, mapped);
@@ -634,13 +636,13 @@
   }
 
   void MapWithCallbackOrDie(uptr beg, uptr size) {
-    CHECK_EQ(beg, reinterpret_cast<uptr>(MmapFixedOrDie(beg, size)));
+    CHECK_EQ(beg, address_range.MapOrDie(beg, size));
     MapUnmapCallback().OnMap(beg, size);
   }
 
   void UnmapWithCallbackOrDie(uptr beg, uptr size) {
     MapUnmapCallback().OnUnmap(beg, size);
-    UnmapOrDie(reinterpret_cast<void *>(beg), size);
+    address_range.Unmap(beg, size);
   }
 
   bool EnsureFreeArraySpace(RegionInfo *region, uptr region_beg,
Index: lib/sanitizer_common/sanitizer_common.h
===================================================================
--- lib/sanitizer_common/sanitizer_common.h
+++ lib/sanitizer_common/sanitizer_common.h
@@ -131,7 +131,8 @@
 class ReservedAddressRange {
  public:
   uptr Init(uptr size, const char *name = nullptr, uptr fixed_addr = 0);
-  uptr Map(uptr fixed_addr, uptr size, bool tolerate_enomem = false);
+  uptr Map(uptr fixed_addr, uptr size);
+  uptr MapOrDie(uptr fixed_addr, uptr size);
   void Unmap(uptr addr, uptr size);
   void *base() const { return base_; }
   uptr size() const { return size_; }
Index: lib/sanitizer_common/sanitizer_fuchsia.cc
===================================================================
--- lib/sanitizer_common/sanitizer_fuchsia.cc
+++ lib/sanitizer_common/sanitizer_fuchsia.cc
@@ -246,8 +246,12 @@
 
 // Uses fixed_addr for now.
 // Will use offset instead once we've implemented this function for real.
-uptr ReservedAddressRange::Map(uptr fixed_addr, uptr map_size,
-                               bool tolerate_enomem) {
+uptr ReservedAddressRange::Map(uptr fixed_addr, uptr map_size) {
+  return reinterpret_cast<uptr>(MmapFixedOrDieOnFatalError(fixed_addr,
+                                                           map_size));
+}
+
+uptr ReservedAddressRange::MapOrDie(uptr fixed_addr, uptr map_size) {
   return reinterpret_cast<uptr>(MmapFixedOrDie(fixed_addr, map_size));
 }
 
Index: lib/sanitizer_common/sanitizer_posix_libcdep.cc
===================================================================
--- lib/sanitizer_common/sanitizer_posix_libcdep.cc
+++ lib/sanitizer_common/sanitizer_posix_libcdep.cc
@@ -339,7 +339,7 @@
 
 uptr ReservedAddressRange::Init(uptr size, const char *name, uptr fixed_addr) {
   if (fixed_addr) {
-    base_ = MmapFixedNoAccess(fixed_addr, size, name);
+    base_ = MmapFixedNoAccess(fixed_addr, size);
   } else {
     base_ = MmapNoAccess(size);
   }
@@ -350,11 +350,11 @@
 
 // Uses fixed_addr for now.
 // Will use offset instead once we've implemented this function for real.
-uptr ReservedAddressRange::Map(uptr fixed_addr, uptr size,
-                               bool tolerate_enomem) {
-  if (tolerate_enomem) {
-    return reinterpret_cast<uptr>(MmapFixedOrDieOnFatalError(fixed_addr, size));
-  }
+uptr ReservedAddressRange::Map(uptr fixed_addr, uptr size) {
+  return reinterpret_cast<uptr>(MmapFixedOrDieOnFatalError(fixed_addr, size));
+}
+
+uptr ReservedAddressRange::MapOrDie(uptr fixed_addr, uptr size) {
   return reinterpret_cast<uptr>(MmapFixedOrDie(fixed_addr, size));
 }
 
Index: lib/sanitizer_common/sanitizer_win.cc
===================================================================
--- lib/sanitizer_common/sanitizer_win.cc
+++ lib/sanitizer_common/sanitizer_win.cc
@@ -237,11 +237,11 @@
 
 // Uses fixed_addr for now.
 // Will use offset instead once we've implemented this function for real.
-uptr ReservedAddressRange::Map(uptr fixed_addr, uptr size,
-                               bool tolerate_enomem) {
-  if (tolerate_enomem) {
-    return reinterpret_cast<uptr>(MmapFixedOrDieOnFatalError(fixed_addr, size));
-  }
+uptr ReservedAddressRange::Map(uptr fixed_addr, uptr size) {
+  return reinterpret_cast<uptr>(MmapFixedOrDieOnFatalError(fixed_addr, size));
+}
+
+uptr ReservedAddressRange::MapOrDie(uptr fixed_addr, uptr size) {
   return reinterpret_cast<uptr>(MmapFixedOrDie(fixed_addr, size));
 }